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    Effects on learning of multimedia animation combined with

    multidimensional concept maps

    Chei-Chang Chiou   a, Li-Chu Tien  b ,  *, Li-Tze Lee  c

    a Department of Accounting, National Changhua University of Education, No.2, Shi-Da Road, Changhua 500, Taiwan, ROC b Department of Hospitality Management, MingDao University, 369, Wen-Hua Road, Peetow, Changhua 52345, Taiwan, ROC c Department of Accounting Information, Overseas Chinese University, No. 100, Chiao Kwang Road, Taichung 407, Taiwan, ROC 

    a r t i c l e i n f o

     Article history:

    Received 21 April 2014

    Received in revised form

    9 September 2014

    Accepted 9 September 2014

    Available online 18 September 2014

    Keywords:

    Computer-mediated communication

    Improving classroom teaching

    Multimedia/hypermedia systems

    Teaching/learning strategies

    a b s t r a c t

    This study investigates whether teaching materials combining multimedia animation and multidimen-

    sional concept maps (MAMCMs) improve learning achievement, retention, and satisfaction more than

    multidimensional concept maps (MCMs), as suggested by Huang et al. (2012) in  Computers  & Education.

    Learning retention, learning achievement, and learning satisfaction associated with two sets of course

    materials were compared in this quasi-experimental study. In total, 114 students from two classes at one

    private university in Taiwan participated in this 6-week teaching experiment. Analytical results indicate

    that learning achievement, learning satisfaction, and learning retention of the MAMCM group were

    better than those of the MCM group. Pedagogical implications and suggestions are given.

    ©  2014 Elsevier Ltd. All rights reserved.

    1. Introduction

    Multimedia materials are preferred by many teachers in current learning environments (Sankey, 2003). Multimedia animation can

    contain words, pictures, sounds, images, and moving pictures. Previous studies indicated that animation improves a learner's ability to

    remember facts and information processing (Holzinger, Kickmeier-Rust, &  Albert, 2008; Schar  &  Zimmermann, 2007). According to Mayer

    (2001), the   “Segmenting Principle”  and   “Coherence Principle”   in multimedia instructional design can model the structure of an entire

    chapter and the relationships among chapters. With sound, action, and images, animation can elucidate complex abstract concepts for

    learners. Additionally, studies have shown that multimedia animation as a teaching tool can help learners understand complex concepts,

    identify misconceptions, and positively impacts learners' motivation, satisfaction, learning achievement, and information processing

    (Dalacosta, Kamariotaki-Paparrigopoulou, Palyvos,  & Spyrellis, 2009; Holzinger et al., 2008; Leung  & Pilgrim, 1995; Mayer & Moreno, 1998;

    Mousavi, Low,  & Sweller, 1995; Tindall-Ford, Chandler,  & Sweller, 1997). Hence, animation is an appropriate teaching material. However,

    good teaching materials should be effective and suited to a student's cognitive level (Holzinger et al., 2008).

    Based on Ausubel's (1968) cognitive learning assimilation theory,  Novak and Gowin (1984) advocated using concept maps for teaching,

    learning, and constructing teaching materials (Huang et al., 2012). Early studies conrmed that applying concept maps for teaching ma-

    terials positively impact motivation, satisfaction, and learning outcomes for learners (Chang, Sung,& Chen, 2002a; Fesmire, Lisner, Forest, &

    Evans, 2003; Gilbert  & Greene, 2001; Simone, Schmid,  & McEwen, 2001). Huang et al. (2012) developed the multidimensional concept map

    (MCM) based on   Miller's (1956)   theory of short-term memory and working memory. This MCM overcomes the shortcomings of the

    traditional complex Novak concept map(NCM) (Adesope &Nesbit, 2013; Amadieu, van Gog, Paas, Tricot,& Marine, 2009) and outperformed

    the NCM and traditional textbook instruction in terms of learning achievement and satisfaction.

    However, according to information processing theory, MCM digital teaching materials (Huang et al., 2012) have one shortcoming; that is,

    an MCM only uses the visual system, which may cause cognitive overload for learners (Deimann  & Keller, 2006). This study overcomes this

    problem and design learning materials that combine multimedia animation and a multidimensional concept map (MAMCM) based on dual-

    coding theory (Paivio, 1986) and cognitive theory of multimedia learning (Mayer, 2001). Two information processing systems exist: the

    *  Corresponding author. Tel.:  þ886 4 887 6660x7833.

    E-mail addresses: [email protected] (C.-C. Chiou),  [email protected] (L.-C. Tien),  [email protected] (L.-T. Lee).

    Contents lists available at ScienceDirect

    Computers & Education

    j o u r n a l h o m e p a g e :   w w w . e l s e v i e r . c om / l o c a t e / c o m p e d u

    http://dx.doi.org/10.1016/j.compedu.2014.09.002

    0360-1315/©

     2014 Elsevier Ltd. All rights reserved.

    Computers & Education 80 (2015) 211e223

    mailto:[email protected]:[email protected]:[email protected]://www.sciencedirect.com/science/journal/03601315http://www.elsevier.com/locate/compeduhttp://dx.doi.org/10.1016/j.compedu.2014.09.002http://dx.doi.org/10.1016/j.compedu.2014.09.002http://dx.doi.org/10.1016/j.compedu.2014.09.002http://dx.doi.org/10.1016/j.compedu.2014.09.002http://dx.doi.org/10.1016/j.compedu.2014.09.002http://dx.doi.org/10.1016/j.compedu.2014.09.002http://www.elsevier.com/locate/compeduhttp://www.sciencedirect.com/science/journal/03601315http://crossmark.crossref.org/dialog/?doi=10.1016/j.compedu.2014.09.002&domain=pdfmailto:[email protected]:[email protected]:[email protected]

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    auditory system and visual system. These systems comprise the dual-coding memory model (Schnotz &  Bannert, 2003). No study has used

    dual-coding theory to assess the impact of multimedia animation combined with concept maps on learning. Therefore, based on dual-

    coding theory and cognitive theory of multimedia learning, this study is the   rst to investigate whether learning achievement and

    learning retention are improved more by MAMCMs than by MCMs.

    Tough (1978)  noted that learning satisfaction is a perception learners of comprised of    “satised,” “happy,”  or   “positive”  feelings in

    contrast to   “unsatisfactory,” “unhappy” and   “negative” feelings. Biehler and Snowman (1990) asserted that linking new concepts with daily

    events will harness learners' attention and interest. The MAMCM materials in this study contain images of real life, fashion, music,

    advertising, and popular images are simple and easily understandable (Anderson, 1987). Therefore, the second purpose of this study is to

    investigate whether learning satisfaction is better with MAMCMs than with MCMs.

    In short, two research purposes of this paper are to examine:

    1. whether MAMCMs improves more students' learning achievement and learning retention than MCMs; and

    2. whether MAMCMs gets better students' learning satisfaction than MCMs.

    2. Review of literature

    In 1984, Novak and Gowin proposed a concept map based on Ausubel's (1968) cognitive learning assimilation theory (Novak  &  Gowin,

    1984). In this theory, a concept mapis composed of propositions and is a graphical representation in twodimensions that uses words linking

    two concept nodes to facilitate meaningful learning (Beyerbach, 1998; Chiou, 2008, 2009). Meaningful learning is active, in-depth, or

    constructive; that is, learners adopt actively new concepts by linking or associating them with concepts in their cognitive structures.

    Knowledge is updated and individualized cognitive structures are existing expanded after such learning (Ausubel 1968; Novak  & Gowin,

    1984). Concept maps, therefore, can promote deep learning.In fact, previous researches have demonstrated that concept mapping can improve student learning. For instance, concept mapping can

    facilitate meaningful learning (Malone  &  Dekkers, 1984), enhance the abilities of students to solve problems and web-based problem-

    solving performance (Hwang, Kuo, Chen,  &  Ho, 2014; Novak, Gowin,  &  Johanson, 1983; Trowbridge &  Wandersee, 1996), decrease student

    learning anxiety ( Jegede, Alaiyemola,  &  Okebukola, 1990), improve reading comprehension and writing ability (Liu, 2011; Liu, Chen,  &

    Chang, 2010), and improve memory and learning effectiveness (Chiou, 2008, 2009; Cliburn, 1990; Huang et al., 2012). Researchers also

    have developed or used computer-assisted concept mapping systems, such as Inspiration, and showed that computer-assisted concept

    mapping can help students construct and revise concept maps, improve the quality of teacher and student interactions, and enhance

    student learning achievement (Anderson-Inman & Horney, 1996; Chang, Sung,  & Chen, 2001; Chu, Hwang,  & Liang, 2014; Hwang et al.,

    2014; Hwang, Yang,  &  Wang, 2013; Liu, 2011; Liu et al., 2010; Yang, Hung, Hwang,  &  Tseng, 2013).

    Furthermore, previous researchers proved that Internet-based teaching materials constructed using a concept map can help students

    construct overall knowledge and improve learning achievement (Chang, Sung,  & Chiou, 2002b; Huang et al., 2012), because thinking and

    memory are neural network functions. Also, a hierarchical concept map links horizontal and vertical concepts in courses for integration,

    classication, and sorting through linking words to express relationships among concepts, allowing students to learn through relationships

    by understanding how new knowledge and existing meaningful structures  t. A graphic presentation can be used to integrate curriculumknowledge and help students construct their personal knowledge (Chiou, 2008, 2009). Therefore, the concept map is ideally suited for

    constructing teaching materials.

    3. Learning design

     3.1. Mayer's cognitive theory for multimedia learning 

    Paivio's (1986) dual-coding theoryasserted people receive cognitive information visually and auditorily. When information is coded into

    language and non-language forms or visual and auditory forms, it can help individuals store information in long-term memory (Kulhavy,

    Stock,  & Kealy, 1993). In 2001, Mayer argued that animation and auditory materials can improve learning effectiveness, and he proposed

    the cognitive theory of multimedia learning by integrating information processing theory (Keefe  &  Jenkins, 1997), dual-coding theory

    (Paivio, 1986), a model of working memory (Baddeley, 1992), and Mayer's (1997) generative theory of multimedia learning (Mayer, 2003;

    Mayer  &  Moreno, 2002, 2003).

    Short-term memory is concerned with such information-related activities as dailyconversations, pictures, animation, and videos. As longas a learner's awareness is aroused, sensory memory can transfer information into short-term memory or long-term memory. When

    designing teaching materials, one must consider both long-term and short-term memory capacities and time constraints. Short-term

    memory encodes information based on audio and semantic codes. Once information attracts learners' interest in visual stimulation,

    sounds, smells, or stimulation acquired by the other sensory organs, this information is stored in short-term memory. Biehler and Snowman

    (1990) asserted that new information should be connected with daily events to retain the interest of learners. Thus, this study designs

    accounting materials using multimedia animation and concept maps that incorporate learners' life experiences to attract their interest and

    attention. By integrating prior knowledge and new knowledge, meaningful learning can be facilitated (Ausubel, 1968). For instance,

    “Merchandising companies” is a general concept.   “Expenses” and   “cost of goods sold” follow this concept in a hierarchical order, such that

    these three concepts become a hierarchy whose structure can benet meaningful learning (Novak et al.,1983) (see Fig.1). Additionally, since

    7e11 is a merchandising company, advisement music for 7e11 is used to  rst attract the attention of learners and daily life images and

    animation features are then used in the map for expositive teaching to increase the interest and attention of learners and enhance their

    internalization of information. According to Holzinger et al. (2008) and Thompson and McGill (2008), teaching materials that incorporate

    visual (images and animation) and audio (sound) information are superior to visual (text and picture) materials alone because it simul-

    taneously stimulates two sensory systems.

    C.-C. Chiou et al. / Computers & Education 80 (2015) 211e 223212

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     3.2. Mayer's theory in designing teaching materials

     3.2.1. Two teaching materials

    The MAMCM teaching material was designed based on Mayer's cognitive model of multimedia learning. Contents were from the

    “Merchandising” and “Inventory” units. This teaching material consisted of 86 image les (visual language system) (Fig. 2) and 35audioles

    (non-language sound system) (Fig. 3). Five colors (light yellow, light green, light blue, pink, and red (in web version)) were used to classify

    the accounts expenses, revenue, cost of goods sold, operating expenses, and non-operating expenses. Terminology in the accounting

    concept maps is marked with a cubic text block. Block size is 2.65 6.8 cm and 3.8 6 cm, font size is 28 pt, and each picture is a concept

    map. Additionally, another feature of the MAMCMs is it was designed for deep and broad learning, which was discussed by Huang et al.(2012) (see Huang et al., 2012, pp. 864e865).

    Fig. 1.   MAMCM on   “Merchandising”.

    Fig. 2.   Image 

    les.

    C.-C. Chiou et al. / Computers & Education 80 (2015) 211e 223   213

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    The MCM refers to the design style by Huang et al. (2012), but does not include multimedia animation. The two digital teaching materials

    were checked by six experts to obtain consensus and assess content validity. The six experts were two accounting teachers, two animation

    experts, and two curriculum specialists.

     3.2.2. The MAMCMs achieves deep and broad learning effectiveness

    When instructors teach “Merchandising” in an entireconcept map without multimedia animation, students may become confused.Thus,

    to reduce the risk of cognitive overload and disorientation, Mayer's cognitive theory of multimedia learning and Paivio's dual-coding theory

    were used to design the teaching material. For instance,  Fig. 4 shows a basic unit. The top-level concept for   “Expenses”  is presented as a

    picture of cash outow with the sound of a cash register. The second-level concept for   “Operating Expenses”  is presented as pictures of 

    water and electricity receipts with the sound of bombs exploding, likening utilities payment to bombs exploding. The concept for   “Non-operating Expenses” refers to expenses or losses that are outside the regular course of business. A picture of a stock market price and sound

    of games for buying stocks are presented as the concept of investment loss.

    Fig. 3.   Audio  les.

    Fig. 4.   MAMCM: basic unit.

    C.-C. Chiou et al. / Computers & Education 80 (2015) 211e 223214

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    These animations help learners memorize course content. Additionally, learning from animated concept maps with daily experiences can

    help students connect tworelevantconcepts with wordsto attain meaningful learning. Forinstance, theword “includes” links “Expense” and

    “Cost of Goods Sold”, and the word   “contents” link low-level concepts such as   “Selling Expenses” and   “Administration Expenses”. Further,

    “Cost of Goods Sold”, “Operating Expenses” and “Non-operating Expenses” are closed at year end in three statements: “Income Statements”,

    “Retained Earnings Statements” and   “Statements of Financial Position”, sequentially (Fig. 5 for the advanced units). The hyperlink between

    three statements can help students acquire a deep and broad understanding of closing entries ( Figs. 6e8) (Huang et al., 2012).

    Anderson (1987) recommended that teaching materials should be in an easy and clear format instead of a dif cult and complex format.

    The use of daily life pictures and sound benets accounting content and enhances long-term recall of learned material (Holzinger et al.,

    2008). The Experimental class was taught using multimedia animation with multidimensional concept maps hyperlink language for ver-

    tical and horizontal connections in accounting teaching materials, while the control class was taught using a MCM without animation,

    sounds, colors, and images (Figs. 9 and 10).

    4. Research design

    4.1. Information processing theory

    The design of MAMCMs in this study is based on information processing theory from cognitive learning theory, which models howlearners absorb, apply, and store knowledge through feelings, attention, conversion, memory, and other internal functions (Atkinson  &

    Fig. 5.  MAMCM: advanced unit.

    Fig. 6.  MAMCM: deepened and broadened learning.

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    Shiffrin, 1968). The information processing sequence in the human brain moves from sensory memory to short-term memory and then to

    long-term memory. Sensory memory exists when an individual receives visual, audio, taste, smell, and touch stimulation and the sensory

    organs then store this information. According to Sperling (1960), when a message is not retained for more than 1 s, memory loss will occur.

    Averbach and Coriell (1961) indicated that an image stays in sensory memory for only 0.25 s, while an audio message is generally retained

    for 5 s (Anderson, 1990). As learners receive a stimulus, they can pay attention to it and code it into another perception, related it to a

    previous perception, or ignore it; however, no stimulus causes messages to be forgotten (Zheng, 1997).

    Short-term memory refers to memories that last for 20e30 s when motive, need, or experience is triggered by information sensory

    receptors. According to Gange (1985), although humans can retain 15e30 concepts every minute, only half are transferred to short-term

    memory. Since time constraints exist for retaining information in short-term memory, without instant processing, information begins to

    fade within 20 s during the moving process from sensory stimuli to cognitive awareness (Peterson  & Peterson, 1959). Miller (1956) showed

    that most people's short-term memory can only store 7  ± 2 units. Therefore, by expanding working memory or linking information with

    meaningful events, the time restriction and capacity limits can be improved.

    Fig. 7.  MAMCM: intensive example 1.

    Fig. 8.  MAMCM: intensive example 2.

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    Long-termmemory is generally permanentmemory. For instance, an elderly personmay be able to recall clearly details about their school and

    loves from over 20 years ago. Long-term memory without a capacity or time limit can store massive amounts of information as long as data are

    classied, integrated, and retained systematically and coded for retrieval. Long-term memory, sensory memory, and short-term memory code

    information differently. Semantic coding and visual coding are preferred by long-term memory. Semantic coding is preferred in language learning,

    while visual coding is prioritized for non-language learning. These two coding types are complementary for learning (Chang, 2003).

    The MAMCM material for teaching in this study is based on information processing theory, visual and auditory dual-coding theory, and

    the concept map construction method (see Huang et al., 2012), which considers Miller's (1956) short-term memory capacity limit, and limits

    the numberof concepts in each digital teaching material in Miller's request scope. Therefore, this material can enhance short-term and long-

    term memory of students.

    4.2. Method

    4.2.1. Experimental design and participants

    This is a nonequivalent quasi-experimental study. Subjects were 114 students in twofreshmen classes (56 in the experimental group and58 in the control group) at one private university in Taiwan. The experimental group was 30 females and 26 males (54% female), and the

    average age was 18 years. While the control group was 34 female and 24 males (59% female), and the average age was 18 years.

    Fig. 9.   MCM: main unit.

    Fig. 10.  MCM: example.

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    All students participated in a 6-week teaching experiment. Independent variables are the two classes. Dependent variables are learning

    achievement, learning satisfaction, and learning retention.

    Beforethis study, neither class had learned about concept maps, such that they had same knowledgelevel. A pretest implemented before

    experiment. The experimental class used MAMCM teach materials, while the control class used MCMs. After the teaching period, each class

    took the same post-test, and after four weeks they took the second post-test to long-term retention.

    To minimize interference variables, such as test, incident, maturity, measurement tool, loss of subject, choice difference, or different

    classroom, thisstudy used the same instructor, teaching hours, textbook, content of the course, test instrument, and requirements for taking

    this course (Borg  &  Gall, 1989; Campbell  &  Stanley, 1963). To eliminate the problem of interference, the pretest was a covariate, while class

    was the independent variable and post-test was a dependent variable. Thus, one-way analysis of covariance (ANCOVA) was applied (Fig. 11).

    4.2.2. Context of the study

    The experimental course is Financial Accounting because it is a required course for the two participating freshmen classes. Learning

    objectives of this course include denition and relationship among different accounting concepts, accounting recording process,  nancial

    statement preparation, and application to practical business situations.

    To construct correctly a  nancial statement, a thorough understanding of the relationships between different accounting concepts is

    essential. The correctness of nancial statements and understanding among different accounting concepts are essential objectives. From this

    viewpoint, researchers (Chiou, 2008; Leauby  &  Brazina, 1998) proposed concept map logic which can build links and cross-links between

    accounting concepts and relationships.

    In addition,  nancial statements are hierarchical structured. Balance Sheet is a general concept which contains total assets, and total

    assets contains current assets while cash as the specic unit under current assets. This hierarchical structure can also be found in the hi-

    erarchical concept map (Chiou, 2008; Leauby   &   Brazina, 1998). Therefore, concept maps in accounting should provide considerable

    assistance to students in terms of learning the logic and relationship germane to  nancial statements.

    The MAMCM digital teaching material, which includes multidimensional concept maps and multimedia animation, was used to teachstudents in the experimental group. While the control class was taught using a MCM without multimedia animation.

    4.2.3. Research instrument 

    4.2.3.1. Learning achievement tests. The pre-test had 25 multiple-choice questions on journalizing, posting, trial balance, and adjusting from

    rst three chapters while the post-test had 25 multiple-choice questions on merchandising and inventory from four and  ve chapters.

    Before the pilot test, questions were examined using a two-way specication table with sections for knowledge, comprehension, appli-

    cation, and analysis. The pilot test was administered to 65 freshmen at one national university in central Taiwan. According to American

    assessment scholar Ebel, distinction criteria for question dif culty should be 0.20e0.80 (Ebel & Frisbie, 1991). According to this standard, 20

    questions worth 5 points each for a total of 100 points were selected for the pretest and post-test. Kuder-Richardson reliability for the

    pretest and post-test, were 0.69 and 0.70, respectively.

    4.2.3.2. Learning satisfaction scale.  Learning satisfaction was assessed for the experimental group (MAMCMs) and control group (MCMs).

    The learning satisfaction scales for these two groups included three factors and was designed based on the computer user satisfaction

    scale by   Doll and Torkzadeh (1988). Three major factors in this learning satisfaction scales contained: teaching material content,knowledge characterization, and individual differences. For instance, one question stated that   “I feel this material helps me learn and

    understand the fundamental accounting concepts”. Cronbach's alpha for the three factors was 0.83, 0.86 and 0.82, and overall scale value

    was 0.93 for the experimental group. The cumulative explained variance was 67.93% for the 13-item scale. For the control group,

    Cronbach's alpha for the three factors was 0.90, 0.88 and 0.84, and that of overall scale was 0.82. The cumulative explained variance was

    70.13% for the 13-item scale. A 5-point Likert scale, ranging from   ‘strongly disagree’ (þ1) to   ‘strongly agree’ (þ5), was used by this learning

    satisfaction questionnaire. Therefore, the maximum score was 65. As a learner's score increased, his/her satisfaction increased and vice

    versa.

    Fig. 11.  Research structure.

    C.-C. Chiou et al. / Computers & Education 80 (2015) 211e 223218

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    4.2.4. Experimental teaching procedure

    The teaching experiment was divided into four steps. The   rst step was preparation and lecturing with traditional digital teaching

    materials on journaling, posting, trial balance, and adjusting. Second, students were administrated a pretest to assess the extent of their

    knowledge. Third, two topics, Merchandising and Inventory, were divided into 12 units and taught using MAMCMs and MCMs for the

    experimental and control classes, respectively. This was a seven-week-long formal teaching experiment with 3 h per week. Learning

    achievement and learning satisfaction were evaluated during week seven. Four weeks after the learning achievement posttest, a learning

    retention test was administered to assess retention of course contentdmemory. Table 1 shows the experimental procedure.

    5. Results

    5.1. The learning achievement of the MAMCM class exceeds that of the MCM class

    Financial Accounting is a hard subject to study. For example, in Taiwan, the passing score for National Certi ed Public Accountant Test is 60.

    In this sense, average score over 60 is very good performance. Average scores for the experimental and control classes on the pretest were

    64.64 and 65.36, respectively; the average score for experimental class was 0.72 lower than that of the control class. In addition, average

    post-test scores for experimental and control classes were 64.10 and 52.60, respectively; the average score for the experimental class was

    11.5 higher than that of the control class (Table 2).

    As pretests scores were not the same for both classes, analytical results may be impacted. Therefore, in this study, pretest score is a

    covariance, posttest score is a dependent variable and class is an independent variable. The ANCOVA analysis was applied to exclude

    interference of pretest scores and account for real differences in posttest scores between the two classes. The ANCOVA analysis can be

    applied since the homogeneity test of regression coef cients was examined and no signicant difference (F  ¼ 1.88, p  ¼ 0.174) was found

    (Table 3).

    After controlling for the interference of covariates, posttest scores of the experimental class and control class differed signicantly

    (F ¼ 5.2, p < .05). This analytical result indicatesthat after excluding the inuence of pretest scores, the experimental class outperformed the

    control class. That is, MAMCMs for instruction were more effective than MCMs.

    5.2. Learning satisfaction of the MAMCM class was better than that of the MCM class

    To test for differences in learning expectations, the MAMCM learning satisfaction scale and the MCM learning satisfaction scale were

    applied. Each question in each instrument was scored 1e5; as total score increased, a student's satisfaction increased. Total teaching ma-

    terials satisfaction score in the experimental group was 47.5 and average score was 3.66 after divided by 13 questions. The average score

    implied that students' satisfaction level in the MAMCM group was near   “agree”. Thus, students in average were satised with MAMCM

    teaching material. However, total teaching materials satisfaction score in the control group was 44.14 and average score was 3.19 after

    divided by 13 questions. The average score impliedthat students' satisfaction level in the MCMgroupwas near “no opinion”. In other words,

    students in the control group did not very satisfy with MCM teaching materials.

    Additionally, a signi

    cant difference (t  ¼

     3.04,  p <

      .01) existed in the independent sample  t -test (see Table 4), meaning that learningsatisfaction differed between the two classes. The learning satisfaction score of the experimental class was higher than that of control class

    by 3.36, and average scores for both the experimental and control groups were 47.50 and 44.14, respectively. Hence, learning satisfaction in

    the MAMCM class was better than that of the MCM class.

    5.3. Course content retention by the MAMCM group was signi cantly better than that of the control group

    Researchers who conducted this study wanted to determine whether retention of course content by the MAMCM class was better than

    that of the MCM class. Thus, post-test was applied four weeks after the experiment end. In MAMCM group, the average scores for post-test

    and content retentionwere 64.1 and 62.32, respectively. It implied that learning retention decline by 1.78 points. On the other hand, in MCM

    group, the average scores for post-test and content retention each were found 52.6 and 46.38, respectively. The learning retention scores

    dropped by 6.22 and implied a great memory loss.

     Table 1

    Teaching experimental procedure.

    Week Activities

    Preparing

    stage1 Design teaching materials and review by experts

    2 Design Learning achievement tests and learning satisfaction scale1e5   1 Lecture with traditional digital teaching materials on contents of journaling, posting, trial balance, and adjusting

    2 Choose one national university in central Taiwan as a pilot test for experimental instruments6e7   1 Pretest: examine students' prior knowledge

    2 Grouping: experimental class uses MAMCMs and control class uses MCMs

    3 Instruction: awareness for experimental teaching materials was announced8e14   1 Experimental class was taught with the MAMCMs and control class was taught with the MCMs. Teaching contents included

    ‘Merchandising’ and   ‘Inventory’ units.

    2 The Achievement test was used as a posttest for both classes after experimental teaching to compare difference between classes and the

    learning satisfaction scale was used to understand students' learning perception and viewpoints for teaching materials in both groups18   1 The achievement test was used to compare learning retention between two classes four weeks after the rst posttest.

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    No signicant difference was found for test of homogeneity for regression coef cients (F ¼ 0.20, p ¼ .66), indicating that the homogeneity

    for regression coef cients was not violated and covariance analysis can be performed. After controlling for the interference of the pretest, a

    signicant difference existed in post-test scores between the twoclasses (F ¼ 71.78, p< .01) (see Table 5), indicating that long-term retention

    of learning by experimental class was better than that of the control class. Therefore, experimental results demonstrate that students taught

    with MAMCMs had better learning retention than those taught with MCMs.

    6. Discussion

    6.1. The MAMCMs can better improve learning achievement than MCMs

    This study found that the MAMCMs can improve learning achievement more than MCMs. The MAMCMs are hierarchical knowledge

    structures with hyperlinks which link nodes of complex relevant concepts. Therefore, they can help students understand the in-

    terrelationships between complex accounting concepts and the structure of the entire textbook (Huang et al., 2012; Liu, 2011). Specically,

    the MAMCMs, using multimedia animation and concept maps with the daily life experiences of learners, can transfer abstract accounting

    concepts to concrete real-life information (Morrison  &  Reeve, 1988). The MAMCMs, therefore, can attract the attention of students and

    improve their learning interest, motivation, and achievement (Dalacosta et al., 2009; Holzinger et al., 2008). Moreover, the MAMCMs canhelp students overcome low learning motivation resulting from complex concepts in traditional concept maps and low learning outcomes

    resulting from limited information processing abilities (Charsky  & Ressler, 2011; Huang et al., 2012; Thompson  & McGill, 2008).

    Additionally, another benet of MAMCMs is that the same accounting content can be presented using two different systems that

    multimedia animation and concept maps are combined. According to  Paivio (1986), dual-coding theory posits two distinct information

    processing systems: auditory and visual. When presenting a concept, using these two systems simultaneously is better than only one

    (Paivio, 1971). Concept maps with an integrated structure and systematic attributes can improve learning effectiveness by helping students

    build knowledge frameworks and understand complex connections among major and minor concepts. However, text and images, with

    belong to the visual system, can cause information and cognitive overload while ignoring the auditory system ( Paivio, 1971). According to

    Tversky, Morrison, and Betrancourt (2002), animated images provide knowledge in detail, display characteristics of an event of context,

    trigger motivation, and help clarify misconceptions. The MAMCM content was designed based on dual-coding theory. In digital material,

    concept maps with multimedia animationwas presented on the same screento accessthe twodifferent processing channels. Thompson and

    McGill (2008) noted that teaching materials with both auditory and visual aspects can decrease information loading and then increase

    learning achievement.

    Furthermore,  Park (1998) and   Schar and Zimmermann (2007)  suggested that good teaching materials should have the following at-tributes: a) attract the attention of learners; b) help memoryencoding and retrieval; c) linking concepts effectively both in depth and width;

    d) be meaningful and structured; and e) explain complex concepts or phenomena. According to arousal theory, an increase in arousal by

    adding, say, entertaining sounds can increase learner attention, such that the amount of material processed by a learner increases, likely

    improving learning performance (Renninger, Hidi,  &  Krapp, 1992; Weiner, 1990). The MAMCMs, which address the auditory and visual

    systems, can attract the attention of learners, help their memory encoding and retrieval, and help them memorize and understand complex

    concepts or phenomena (Dalacosta et al., 2009; Mayer  &  Moreno, 1998; Mousavi et al., 1995). Therefore, experimental results in this study

     Table 2

    Descriptive statistics of pretest and post-test scores for two classes.

    Class Female Male Student number Pretest results Post-test results

    Mean SD Mean SD

    Experimental 30 26 56 64.64 11.8 64.1 12.8

    Control 34 24 58 65.36 11.1 52.6 14.3

    Note. The maximum score of pretest for the experimental class was 84, while the maximum score of pretest for the control class was 88. The maximum score of post-test for

    the experimental class was 84, while the maximum score of post-test for the control class was 84. The Kolmogorove

    Smirnov tests of normal distribution showed that bothpretest and post-test achievement measures were normalized, D ¼ 0.76, p ¼ 0.11; D ¼ 0.81, p ¼ 0.06.

     Table 3

    Post-test scores of one-way ANCOVA.

    Variation Df SS MS   F 

    Class 1 719.33 719.33 5.20*

    Pretest score 1 5237.36 5237.36 37.86**

    Homogeneity test 1 259.31 259.31 1.88

    * p  <   .05, ** p  <  .01.

     Table 4

    Comparison of learning satisfaction between two classes.

    Class Number Mean SD   t 

    Experimental 56 47.50 5.31 3.04**

    Control 58 44.14 6.42

    ** p <

     .01.

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    suggest that MAMCMs attract the attention of learners and improve their learning achievement. Thus, the MAMCMs can results in better

    learning outcomes than MCMs.

    6.2. MAMCMs generate higher learning satisfaction than MCMs

    Experimental results also show that students have higher learning satisfaction when taught with MAMCMs than when taught with

    MCMs. Learners typically prefer teaching materials that are related to daily life. Such material that also stimulates the auditory and visual

    sensory organs of learners and attracts their attention can improve their interest in learning and satisfaction.  Biehler and Snowman (1990)

    argued that newconcepts should be connected to daily events to attract the attention and interest of learners. In this study, MAMCMs based

    on life experiences and content knowledge were designed using pictures, fashion, music, advertising, and popular images. When connected

    to real life, teaching materials can be easily understood and enhance the learning interests of students (Anderson, 1987).

    According to literature, learners are more attentive to colorful images and animation than black and white materials ( Adesope  & Nesbit,

    2013; Holzinger et al., 2008; Nesbit  &  Adesope, 2011; Pett  &  Wilson, 1996; Schwier, Misanchuk,  &  Boling, 2000). Learning satisfaction is a

    feeling. One can determine whether the learning needs of students are met and learning goals are achieved by examining the gap between

    expectations and outcomes. When the gap between expectations and outcomes is small, the learning satisfaction of students is high. With

    increased motivation, students can continue learning and  nd satisfaction and interest. The MAMCMs in this study attracted the attention

    and interest of students by compiling materials with daily life experiences and creating content using colorful pictures, fashion, music,

    advertisements, and popular images. The MAMCMs, therefore, can improve learning satisfaction better than MCMs.

    6.3. MAMCMs generate better retention in long-term memory than MCMs

    The MAMCM content helped learners transfer and generalize knowledge and improved long-term memory. Generalization theory from

    transfer of learning was proposed by Judd in 1908. According to this theory, knowledge or skills learned in stage A can be transferred to stage

    B once a reaction is triggered by a stimulus. The expansion phenomenon of learning is called transfer of learning while the previous learning

    effect will impact new learning ( Judd, 1908). Transfer of learning occurs when interaction exists among existing knowledge, skills, methods,

    attitudes, and new knowledge or new skills (Fu, Man, Leung,& Tan, 2006). Transfer of learning is often regarded as the ultimate educational

    goal; that is, learners apply knowledge to a new context to reach a high degree of achievement. According to Huang (1998) and Bransford,Vye, Bateman, Brophy, and Roselli (2004), learning by understanding and connecting content to real life experiences facilitates transfer of 

    learning performance. For instance, transfer of learning occurswhen external stimuli and cognitivestructures arevery similar. Once learners

    can transfer and generalize their learning, their knowledge and skills can be retained in long-term memory and their abilities and learning

    achievement improve (Westling &  Fox, 2000). In this study, the MAMCM materials, which contained real-life images and animation, were

    vivid and linked to real experiences, helping learners transfer to and categorize knowledge in long-term memory.

    Additionally, when learning, students should be equipped with knowledge of their intrinsic cognitive level and external stimuli and

    interact with external environments. Learners receive stimulation through their sensory receptors. Attention is processed in short-term

    memory and knowledge stored in long-term memory can be transferred to encoding memory for later retrieval ( Chou, 2011). How

    retrieve information from long-term memory and apply this information to produce more memory retention is an important issue. Ac-

    cording to Bower, Clark, Lesgold, and Winzenz (1969), people can recall 19% of their random and disorganized memories, but 65% from

    hierarchical storage. Long-term memory without capacity or time limits can store massive amounts of information systematically. However,

    data are classied, integrated, and retained systematically in long-term memory, where only meaningful and structural information can be

    stored (Chang, 2003). Therefore, teaching materials should be organized, structured, and systematic for retention in and retrieval from long-

    term memory. This study used teaching materials with multidimensional visual diagrams to organize and integrate multimedia sounds,

    motion, and daily events or experiences to connect knowledge and materials and help learners transfer information to long-term memory

    for later retrieval (Chiou, 2003; Jacobs-Lawson  &   Hershey, 2002). Therefore, learning retention in long-term memory was better with

    MAMCM material than with MCM material.

    7. Conclusion

    Previous studies demonstrated that multimedia animation and concept maps in teaching materials positively impact teaching and

    learning in such subjects such as mathematics, physics, chemistry, biology, and medicine. However, concept maps alone only use the visual

    system and ignore the auditory system, possibly causing visual system overload and wasting auditory resources. Teaching materials with

    multimedia animation provide stimuli that attract the attention of learners and make learning fun. However, learners may suffer cognitive

    overload and learning disorientation. Thus, MAMCMs, which take advantage of two sensory systems, can provide cues for subsequent

    integration and recall. They can help learners construct their own cognitive structures and ef ciently transfer their knowledge into practice,

    such that good learning effectiveness is achieved (Huang et al., 2012; Mayer  &  Moreno, 1998; Mousavi et al., 1995; Schnotz, 2005; Tindall-

    Ford et al., 1997). Therefore, the MAMCM material is this study clearly demonstrated its worth as digital teaching material.

     Table 5

    One-way ANCOVA of tracking post-test scores for two classes.

    Variation Df SS MS   F 

    Class 1 7550.981 7550.981 71.78**

    Pretest score 1 3411.426 3411.426 32.43**

    Homogeneity test 1 20.688 20.688 .20

    Note. The average scores of tracking post-test for experimental and control classes are 62.32 and 46.38, respectively.

    ** p  <  .01.

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     Acknowledgments

    This study is supported in part by the Ministry of Science and Technology of the Republic of China under contract numbers NSC 102-

    2628-H-018-001.

    References

    Adesope, O. O., & Nesbit, J. C. (2013). Animated and static concept maps enhance learning from spoken narration.  Learning and Instruction, 27 , 1e10.

    Amadieu, F., van Gog, T., Paas, F., Tricot, A., & Marine, C. (2009). Effects of prior knowledge and concept-map structure on disorientation, cognitive load, and learning. Learning and Instruction, 19, 376e386.

    Anderson, J. R. (1987). Skill acquisition: compilation of weak-method problem solutions.  Psychological Review, 94, 192e210.Anderson, J. R. (1990). The adaptive nature of human categorization.  Psychological Review, 98, 409e429.Anderson-Inman, L., & Horney, M. (1996). Computer-based concept mapping: enhancing literacy with tools for visual thinking. Journal of Adolescent and Adult Literacy, 40 (4),

    302e306.Atkinson, R. L., & S hiffrin, R. M. (1968). Human memory: a proposed system and control processes. In K. W. Spence (Ed.),  The psychology of learning and motivation: Advances in

    research and theory. New York: Academic Press.Ausubel, D. P. (1968).  Educational psychology: A cognitive view. New York: Holt, Rinehart  &   Winston.Averbach, E., & Coriell, A. H. (1961). Short-term memory in vision.  Bell System Technical Journal, 40, 309e328.Baddeley, A. D. (1992). Working memory.  Science, 255, 556e559.Beyerbach, B. A. (1998). Development a technical vocabulary: preserves teachers' concept maps.  Teaching and Teacher Education, 4(4), 339e347.Biehler, R. F., & Snowman, J. (1990).  Psychology applied to teaching  (6th ed.). Boston, MA: Houghton Mif in.Borg, W. R., & Gall, M. D. (1989).  Educational research: An introduction. New York: Longman.Bower, G. H., Clark, M. C., Lesgold, A. M., & Winzenz, D. (1969). Hierarchical retrieval schemes in recall of categorized word lists.  Journal of Verbal Learning and Verbal Behavior,

    8, 323e343.Bransford, J. D., Vye, N., Bateman, H., Brophy, S., & Roselli, R. (2004). Vanderbilt's Amigo3 project: knowledge of how people learn enters cyberspace. In T. Duffy, & J. Kirkley

    (Eds.), Learner-centered theory and practice in distance education. Mahwah, NJ: Erlbaum.Campbell, D. T., & Stanley, J. C. (1963).  Experimental and quasi-experimental designs for research. Chicago: R. McNally.Chang, C. X. (2003).  Educational psychology. Taipei: Dong-Hua.Chang, K. E., Sung, Y. T., & Chen, I. D. (2002a). The effect of concept mapping to enhance text comprehension and summarization.   Journal of Experimental Education, 71(1),

    5e23.Chang, K. E., Sung, Y. T., & Chen, S. F. (2001). Learning through computer-based concept mapping with scaffolding aid.  Journal of Computer Assisted Learning, 17 (1), 21e33.Chang, K. E., Sung, Y. T., & Chiou, S. K. (2002b). Use of hierarchical hyper concept map in web-based courses.   Journal of Educational Computing Research, 27 (4), 335e353.Charsky, D., & Ressler, W. (2011).   “Games are made for fun”: lessons on the effects of concept maps in the classroom use of computer games.  Computers  &  Education, 56 ,

    604e615.Chiou, C. C. (2008). The effect of concept mapping on students' learning achievements and interests.   Innovations in Education and Teaching International, 45(4), 375e387.Chiou, C. C. (2009). Effects of concept mapping strategy on learning performance in business and economics statistics.  Teaching in Higher Education, 14(1), 55e69.Chiou, H. F. (2003).  The effects of multimedia interface on elementary students' learning motivation. Thesis of Department of Educational Technology of National Pingtung

    University of Education, Taiwan.Chou, B. H. (2011). The improvement strategy of Chinese-character-teaching based on transfer of learning.   Journal of National Taipei Education University, 42(2), 1e22.Chu, H. C., Hwang, G. J., & Liang, Y. R. (2014). A cooperative computerized concept mapping approach to improving students' learning performance in web-based information-

    seeking activities.   Journal of Computers in Education, 1(1), 19e33.Cliburn, J. W. (1990). Concept maps to promote meaningful learning.  Journal of College Science Teaching, 19(4), 212e217.Dalacosta, K., Kamariotaki-Paparrigopoulou, M., Palyvos, J. A., & Spyrellis, N. (2009). Multimedia application with animated cartoons for teaching science in elementary.

    Computers &  Educations, 52, 741e748.Deimann, M., & Keller, J. M. (2006). Volitional aspects of multimedia learning.   Journal of Educational Multimedia and Hypermedia, 15(2), 137e158.

    Doll, W. J., & Torkzadeh, G. (1988). The measurement of end-user computing satisfaction.  MIS Quarterly, 12(2), 259e

    274.Ebel, R. L., & Frisbie, D. A. (1991).  Essentials of educational measurement . Englewood Cliffs, NJ: Prentice Hall.Fesmire, M., Lisner, C. P., Forest, P. R., & Evans, W. H. (2003). Concept maps: a practical solution for completing functional behavior assessment.  Education  & Treatment of 

    Children, 26 , 89e104.Fu, C. L., Man, G. W., Leung, C. Y., & Tan, C. (2006). Some strategies of transfer of learning for mathematics.  Journal of Luoyang University, 21(1), 110e112.Gange, E. D. (1985).  The cognitive psychology of school learning . Boston: Little, Brown  &  Company.Gilbert, N. J., & Greene, B. A. (2001). College students' collaborative use of inspiration to generate concept maps in an educational technology class.   Journal of Educational

    Technology Systems, 30, 389e402.Holzinger, A., Kickmeier-Rust, M., & Albert, D. (2008). Dynamic media in computer science education; content complexity and learning performance: is less more? Educational

    Technology  &  Society, 11(1), 279e290.Huang, W. Y. (1998).  The research of generalization on sport skill learning transfer . Thesis of Department of Education of University of Taipei, Taiwan .Huang, H. S., Chiou, C. C., Chiang, H. K., Lai, S. H., Huang, C. Y., & Chou, Y. W. (2012). Effects of multidimensional concept maps on fourth graders' learning in web-based

    computer course.  Computers  &  Education, 58(3), 863e873.Hwang, G. J., Kuo, F. R., Chen, N. S., & Ho, H. J. (2014). Effects of an integrated concept mapping and web-based problem-solving approach on students' learning achievements,

    perceptions and cognitive loads.  Computers  &  Education, 71, 77e86.Hwang, G. J., Yang, L. H., & Wang, S. Y. (2013). A concept map-embedded educational computer game for improving students' learning performance in natural science courses.

    Computers  &  Education, 69(1), 121e130. Jacobs-Lawson, J. M., & Hershey, D. A. (2002). Concept maps as an assessment tool in psychology courses.  Methods  &  Techniques, 29(1), 25e29. Jegede, O. J., Alaiyemola, F. F., & Okebukola, P. A. (1990). The effect of concept mapping on students' anxiety and achievement in biology. Journal of Research in Science Teaching,

     27 , 951e

    960. Judd, D. H. (1908). The relation of special training to general intelligence. Educational Review, 36 , 28e42.Keefe, J. W., & Jenkins, J. M. (1997).   Instruction and the learning environment . NY: Eye On Education, Inc.Kulhavy, R. W., Stock, W. A., & Kealy, W. A. (1993). How geographic maps increase recall of instructional text. Educational Technology Research  &  Development, 41(4), 47e62.Leauby, B. A., & Brazina, P. (1998). Concept mapping: potential uses in accounting education.  Journal of Accounting Education, 16 (1), 123e138.Leung, Y. K., & Pilgrim, C. J. (1995). Multimedia animation to enhance learning complex concepts in data communications. In   Proceedings of 12th Annual Conference of the

     Australian Society for Computers in Learning in Tertiary Education (ASCILITE), Melbourne.Liu, P. L. (2011). A study on the use of computerized concept mapping to assist ESL learners' writing.  Computers  &  Education, 57 , 2548e2558.Liu, P. L., Chen, C. J., & Chang, Y. J. (2010). Effects of a computer-assisted concept mapping learning strategy on EFL college students' English reading comprehension. Computers

    & Education, 54, 436e445.Malone, J., & Dekkers, J. (1984). The concept maps as an aid to instruction in science and mathematics.  School Science and Mathematics, 84(3), 220e231.Mayer, R. E. (1997). Multimedia learning: are we asking the right questions.  Educational Psychologist, 32(1), 1e19.Mayer, R. E. (2001).  Multimedia learning . New York: Cambridge University press.Mayer, R. E. (2003). The promise of multimedia learning: using the same instructional design methods across different media.  Learning and Instruction, 13(2), 125e139.Mayer, R. E., & Moreno, R. (1998). A split attention effect in multimedia learning: evidence for dual processing system in working memory.  Journal of Educational Psychology,

    90(2), 312e320.Mayer, R. E., & Moreno, R. (2002). Animation as an aid to multimedia learning.  Educational Psychology Review, 14(1), 87e99.Mayer, R. E., & Moreno, R. (2003). Nine ways to reduce cognitive load in multimedia learning.  Education Psychologist, 38(1), 43e52.

    Miller, G. A. (1956). The magical number seven, plus or minus two: some limits on our capacity for processing information.  Psychological Review, 63, 81e

    97.

    C.-C. Chiou et al. / Computers & Education 80 (2015) 211e 223222

    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60-1315(14)00202-4/sref39http://refhub.elsevier.com/S0360-1315(14)00202-4/sref39http://refhub.elsevier.com/S0360-1315(14)00202-4/sref39http://refhub.elsevier.com/S0360-1315(14)00202-4/sref39http://refhub.elsevier.com/S0360-1315(14)00202-4/sref40http://refhub.elsevier.com/S0360-1315(14)00202-4/sref40http://refhub.elsevier.com/S0360-1315(14)00202-4/sref40http://refhub.elsevier.com/S0360-1315(14)00202-4/sref40http://refhub.elsevier.com/S0360-1315(14)00202-4/sref40http://refhub.elsevier.com/S0360-1315(14)00202-4/sref41http://refhub.elsevier.com/S0360-1315(14)00202-4/sref41http://refhub.elsevier.com/S0360-1315(14)00202-4/sref41http://refhub.elsevier.com/S0360-1315(14)00202-4/sref41http://refhub.elsevier.com/S0360-1315(14)00202-4/sref41http://refhub.elsevier.com/S0360-1315(14)00202-4/sref41http://refhub.elsevier.com/S0360-1315(14)00202-4/sref42http://refhub.elsevier.com/S0360-1315(14)00202-4/sref42http://refhub.elsevier.com/S0360-1315(14)00202-4/sref42http://refhub.elsevier.com/S0360-1315(14)00202-4/sref42http://refhub.elsevier.com/S0360-1315(14)00202-4/sref43http://refhub.elsevier.com/S0360-1315(14)00202-4/sref43http://refhub.elsevier.com/S0360-1315(14)00202-4/sref43http://refhub.elsevier.com/S0360-1315(14)00202-4/sref44http://refhub.elsevier.com/S0360-1315(14)00202-4/sref44http://refhub.elsevier.com/S0360-1315(14)00202-4/sref44http://refhub.elsevier.com/S0360-1315(14)00202-4/sref44http://refhub.elsevier.com/S0360-1315(14)00202-4/sref44http://refhub.elsevier.com/S0360-1315(14)00202-4/sref45http://refhub.elsevier.com/S0360-1315(14)00202-4/sref45http://refhub.elsevier.com/S0360-1315(14)00202-4/sref45http://refhub.elsevier.com/S0360-1315(14)00202-4/sref45http://refhub.elsevier.com/S0360-1315(14)00202-4/sref45http://refhub.elsevier.com/S0360-1315(14)00202-4/sref46http://refhub.elsevier.com/S0360-1315(14)00202-4/sref46http://refhub.elsevier.com/S0360-1315(14)00202-4/sref46http://refhub.elsevier.com/S0360-1315(14)00202-4/sref47http://refhub.elsevier.com/S0360-1315(14)00202-4/sref47http://refhub.elsevier.com/S0360-1315(14)00202-4/sref47http://refhub.elsevier.com/S0360-1315(14)00202-4/sref47http://refhub.elsevier.com/S0360-1315(14)00202-4/sref47http://refhub.elsevier.com/S0360-1315(14)00202-4/sref47http://refhub.elsevier.com/S0360-1315(14)00202-4/sref48http://refhub.elsevier.com/S0360-1315(14)00202-4/sref48http://refhub.elsevier.com/S0360-1315(14)00202-4/sref48http://refhub.elsevier.com/S0360-1315(14)00202-4/sref48http://refhub.elsevier.com/S0360-1315(14)00202-4/sref48http://refhub.elsevier.com/S0360-1315(14)00202-4/sref49http://refhub.elsevier.com/S0360-1315(14)00202-4/sref49http://refhub.elsevier.com/S0360-1315(14)00202-4/sref49http://refhub.elsevier.com/S0360-1315(14)00202-4/sref49http://refhub.elsevier.com/S0360-1315(14)00202-4/sref50http://refhub.elsevier.com/S0360-1315(14)00202-4/sref50http://refhub.elsevier.com/S0360-1315(14)00202-4/sref50http://refhub.elsevier.com/S0360-1315(14)00202-4/sref50http://refhub.elsevier.com/S0360-1315(14)00202-4/sref51http://refhub.elsevier.com/S0360-1315(14)00202-4/sref51http://refhub.elsevier.com/S0360-1315(14)00202-4/sref51http://refhub.elsevier.com/S0360-1315(14)00202-4/sref52http://refhub.elsevier.com/S0360-1315(14)00202-4/sref52http://refhub.elsevier.com/S0360-1315(14)00202-4/sref52http://refhub.elsevier.com/S0360-1315(14)00202-4/sref52http://refhub.elsevier.com/S0360-1315(14)00202-4/sref52http://refhub.elsevier.com/S0360-1315(14)00202-4/sref53http://refhub.elsevier.com/S0360-1315(14)00202-4/sref53http://refhub.elsevier.com/S0360-1315(14)00202-4/sref53http://refhub.elsevier.com/S0360-1315(14)00202-4/sref53http://refhub.elsevier.com/S0360-1315(14)00202-4/sref53http://refhub.elsevier.com/S0360-1315(14)00202-4/sref54http://refhub.elsevier.com/S0360-1315(14)00202-4/sref54http://refhub.elsevier.com/S0360-1315(14)00202-4/sref54http://refhub.elsevier.com/S0360-1315(14)00202-4/sref54http://refhub.elsevier.com/S0360-1315(14)00202-4/sref55http://refhub.elsevier.com/S0360-1315(14)00202-4/sref55http://refhub.elsevier.com/S0360-1315(14)00202-4/sref55http://refhub.elsevier.com/S0360-1315(14)00202-4/sref55http://refhub.elsevier.com/S0360-1315(14)00202-4/sref56http://refhub.elsevier.com/S0360-1315(14)00202-4/sref56http://refhub.elsevier.com/S0360-1315(14)00202-4/sref56http://refhub.elsevier.com/S0360-1315(14)00202-4/sref56http://refhub.elsevier.com/S0360-1315(14)00202-4/sref56http://refhub.elsevier.com/S0360-1315(14)00202-4/sref56http://refhub.elsevier.com/S0360-1315(14)00202-4/sref55http://refhub.elsevier.com/S0360-1315(14)00202-4/sref55http://refhub.elsevier.com/S0360-1315(14)00202-4/sref54http://refhub.elsevier.com/S0360-1315(14)00202-4/sref54http://refhub.elsevier.com/S0360-1315(14)00202-4/sref53http://refhub.elsevier.com/S0360-1315(14)00202-4/sref53http://refhub.elsevier.com/S0360-1315(14)00202-4/sref53http://refhub.elsevier.com/S0360-1315(14)00202-4/sref52http://refhub.elsevier.com/S0360-1315(14)00202-4/sref52http://refhub.elsevier.com/S0360-1315(14)00202-4/sref51http://refhub.elsevier.co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    Morrison, C., & Reeve, J. (1988). Effect of instruction and undergraduate major on qualitative skill analysis.  Journal of Human Movement Studies, 15, 291e297.Mousavi, S. Y., Low, R., & Sweller, J. (1995). Reducing cognitive load by mixing auditory and visual presentation modes.  Journal of Educational Psychology, 87 (2), 319e334.Nesbit, J. C., & Adesope, O. O. (2011). Learning from animated concept maps with concurrent audio narration.   Journal of Experimental Education, 79, 209e230.Novak, J. D., & Gowin, D. B. (1984).  Learning how to learn. New York: Cambridge University Press.Novak, J. D., Gowin, D. B., & Johansen, G. T. (1983). The use of concept mapping and knowledge vee mapping with junior high school science students.  Science Education, 67 ,

    625e645.Paivio, A. (1971).  Imagery and verbal processes. New York: Holt, Rinehart and Winston.Paivio, A. (1986).  Mental representation: A dual coding approach. Oxford, England: Oxford University Press.Park, O. (1998). Visual displays and contextual presentations in computer-based instruction.  Educational Technology Research and Development, 46 (3), 37e50.Peterson, L. R., & Peterson, M. J. (1959). Short-term retention of individual verbal items.  Journal of Experimental Psychology, 58, 193e198.

    Pett, D., & Wilson, T. (1996). Color research and it application to the design of instructional materials.  Educational Technology Research and Development, 44(3), 19e

    35.Renninger, K. A., Hidi, S., & Krapp, A. (Eds.). (1992).   The role of interest in learning and development . Hillsdale, NJ: Erlbaum.Sankey, M. D. (2003). Visual and multiple representation in learning materials: an issue of literacy. In  Create.ed 2003: eLearning for the Creative Industries, 2 Oct 2003,

    Melbourne, Australia.Schar, S. G., & Zimmermann, P. G. (2007). Investigating means to reduce cognitive load from animations: applying differentiated measures of knowledge representation.

     Journal of Research on Technology in Education, 40(1), 64e78.Schnotz, W. (2005). Cognitive theory of multimedia learning. In R. E. Mayer (Ed.),   The Cambridge handbook of multimedia learning  (pp. 49e70). New Jersey: Cambridge

    University Press.Schnotz, W., & Bannert, M. (2003). Construction and interference in learning from multiple representations.  Learning and Instruction, 13, 141e156.Schwier, R., Misanchuk, E., & Boling, E. (2000). Discourse on designing an illustrated hypermedia book.   Journal of Educational Multimedia and Hypermedia, 9(3), 223e251.Simone, C. D., Schmid, R. F., & McEwen, L. A. (2001). Supporting the learning process with collaborative concept mapping using computer-based communication tools and

    process. Education Research  &  Evaluation, 7 , 263e283.Sperling, E. A. (1960). The information available in brief visual presentations.  Psychological Monographs: General and Applied, 74, 1e28.Thompson, N., & McGill, T. J. (2008). Multimedia and cognition examining the effect of applying cognitive principles to the design of instructional materials.  Educational

    Computing Research, 39(2), 143e159.Tindall-Ford, S., Chandler, P., & Sweller, J. (1997). When two sensory modes are better than one.  Journal of Experimental Psychology, 3(4), 257e287.Tough, A. (1978). Major learning efforts: recent research and future directions.  Adult Education, 28(4), 250e263.Trowbridge, J. E., & Wandersee, J. H. (1996). How do graphics presented during college biology lessons affect students' learning.   Journal of College Science Teaching, 26 (1),

    54e57.Tversky, B., Morrison, J. B., & Betrancourt, M. (2002). Animated: can it facilitate?   International Journal of Human-Computer Studies, 57 , 247

    e262.

    Weiner, B. (1990). History of motivational research in education.  Journal of Educational Psychology, 82, 616e622.Westling, D. L., & Fox, L. (2000).  Teaching students with severe disabilities  (2nd ed.). Upper Saddle River, NJ: Merrill.Yang, C. C., Hung, C. M., Hwang, G. J., & Tseng, S. S. (2013). An evaluation of the learning effectiveness of concept map-based science book reading via mobile devices.

    Educational Technology  &  Society, 16 (3), 167e178.Zheng, Z. M. (1997).  Cognitive psychology: Theory and practice. Taipei: Laurel.

    C.-C. Chiou et al. / Computers & Education 80 (2015) 211e 223   223

    http://refhub.elsevier.com/S0360-1315(14)00202-4/sref57http://refhub.elsevier.com/S0360-1315(14)00202-4/sref57http://refhub.elsevier.com/S0360-1315(14)00202-4/sref57http://refhub.elsevier.com/S0360-1315(14)00202-4/sref57http://refhub.elsevier.com/S0360-1315(14)00202-4/sref57http://refhub.elsevier.com/S0360-1315(14)00202-4/sref58http://refhub.elsevier.com/S0360-1315(14)00202-4/sref58http://refhub.elsevier.com/S0360-1315(14)00202-4/sref58http://refhub.elsevier.com/S0360-1315(14)00202-4/sref58http://refhub.elsevier.com/S0360-1315(14)00202-4/sref58http://refhub.elsevier.com/S0360-1315(14)00202-4/sref59http://refhub.elsevier.com/S0360-1315(14)00202-4/sref59http://refhub.elsevier.com/S0360-1315(14)00202-4/sref59http://refhub.elsevier.com/S0360-1315(14)00202-4/sref59http://refhub.elsevier.com/S0360-1315(14)00202-4/sref60http://refhub.elsevier.com/S0360-1315(14)00202-4/sref60http://refhub.elsevier.com/S0360-1315(14)00202-4/sref60http://refhub.elsevier.com/S0360-1315(14)00202-4/sref61http://refhub.elsevier.com/S0360-1315(14)00202-4/sref61http://refhub.elsevier.com/S0360-1315(14)00202-4/sref61http://refhub.elsevier.com/S0360-1315(14)00202-4/sref61http://refhub.elsevier.com/S0360-1315(14)00202-4/sref61http://refhub.elsevier.com/S0360-1315(14)00202-4/sref62http://refhub.elsevier.com/S0360-1315(14)00202-4/sref62http://refhub.elsevier.com/S0360-1315(14)00202-4/sref62http://refhub.elsevier.com/S0360-1315(14)00202-4/sref63http://refhub.elsevier.com/S0360-1315(14)00202-4/sref63http://refhub.elsevier.com/S0360-1315(14)00202-4/sref63http://refhub.elsevier.com/S0360-1315(14)00202-4/sref64http://refhub.elsevier.com/S0360-1315(14)00202-4/sref64http://refhub.elsevier.com/S0360-1315(14)00202-4/sref64http://refhub.elsevier.com/S0360-1315(14)00202-4/sref64http://refhub.elsevier.com/S0360-1315(14)00202-4/sref64http://refhub.elsevier.com/S0360-1315(14)00202-4/sref65http://refhub.elsevier.com/S0360-1315(14)00202-4/sref65http://refhub.elsevier.com/S0360-1315(14)00202-4/sref65http://refhub.elsevier.com/S0360-1315(14)00202-4/sref65http://refhub.elsevier.com/S0360-1315(14)00202-4/sref66http://refhub.elsevier.com/S0360-1315(14)00202-4/sref66http://refhub.elsevier.com/S0360-1315(14)00202-4/sref66http://refhub.elsevier.com/S0360-1315(14)00202-4/sref66http://refhub.elsevier.com/S0360-1315(14)00202-4/sref67http://refhub.elsevier.com/S0360-1315(14)00202-4/sref67http://refhub.elsevier.com/S0360-1315(14)00202-4/sref67http://refhub.elsevier.com/S0360-1315(14)00202-4/sref68http://refhub.elsevier.com/S0360-1315(14)00202-4/sref68http://refhub.elsevier.com/S0360-1315(14)00202-4/sref68http://refhub.elsevier.com/S0360-1315(14)00202-4/sref69http://refhub.elsevier.com/S0360-1315(14)00202-4/sref69http://refhub.elsevier.com/S0360-1315(14)00202-4/sref69http://refhub.elsevier.com/S0360-1315(14)00202-4/sref69http://refhub.elsevier.com/S0360-1315(14)00202-4/sref70http://refhub.elsevier.com/S0360-1315(14)00202-4/sref70http://refhub.elsevier.com/S0360-1315(14)00202-4/sref70http://refhub.elsevier.com/S0360-1315(14)00202-4/sref70http://refhub.elsevier.com/S0360-1315(14)00202-4/sref70http://refhub.elsevier.com/S0360-1315(14)00202-4/sref70http://refhub.elsevier.com/S0360-1315(14)00202-4/sref71http://refhub.elsevier.com/S0360-1315(14)00202-4/sref71http://refhub.elsevier.com/S0360-1315(14)00202-4/sref71http://refhub.elsevier.com/S0360-1315(14)00202-4/sref71http://refhub.elsevier.com/S0360-1315(14)00202-4/sref72http://refhub.elsevier.com/S0360-1315(14)00202-4/sref72http://refhub.elsevier.com/S0360-1315(14)00202-4/sref72http://refhub.elsevier.com/S0360-1315(14)00202-4/sref72http://refhub.elsevier.com/S0360-1315(14)00202-4/sref72http://refhub.elsevier.com/S0360-1315(14)00202-4/sref73http://refhub.elsevier.com/S0360-1315(14)00202-4/sref73http://refhub.elsevier.com/S0360-1315(14)00202-4/sref73http://refhub.elsevier.com/S0360-1315(14)00202-4/sref73http://refhub.elsevier.com/S0360-1315(14)00202-4/sref73http://refhub.elsevier.com/S0360-1315(14)00202-4/sref73http://refhub.elsevier.com/S0360-1315(14)00202-4/sref73http://refhub.elsevier.com/S0360-1315(14)00202-4/sref74http://refhub.elsevier.com/S0360-1315(14)00202-4/sref74http://refhub.elsevier.com/S0360-1315(14)00202-4/sref74http://refhub.elsevier.com/S0360-1315(14)00202-4/sref74http://refhub.elsevier.com/S0360-1315(14)00202-4/sref75http://refhub.elsevier.com/S0360-1315(14)00202-4/sref75http://refhub.elsevier.com/S0360-1315(14)00202-4/sref75http://refhub.elsevier.com/S0360-1315(14)00202-4/sref75http://refhub.elsevier.com/S0360-1315(14)00202-4/sref75http://refhub.elsevier.com/S0360-1315(14)00202-4/sref76http://refhub.elsevier.com/S0360-1315(14)00202-4/sref76http://refhub.elsevier.com/S0360-1315(14)00202-4/sref76http://refhub.elsevier.com/S0360-1315(14)00202-4/sref76http://refhub.elsevier.com/S0360-1315(14)00202-4/sref77http://refhub.elsevier.com/S0360-1315(14)00202-4/sref77http://refhub.elsevier.com/S0360-1315(14)00202-4/sref77http://refhub.elsevier.com/S0360-1315(14)00202-4/sref77http://refhub.elsevier.com/S0360-1315(14)00202-4/sref78http://refhub.elsevier.com/S0360-1315(14)00202-4/sref78http://refhub.elsevier.com/S0360-1315(14)00202-4/sref78http://refhub.elsevier.com/S0360-1315(14)00202-4/sref78http://refhub.elsevier.com/S0360-1315(14)00202-4/sref78http://refhub.elsevier.com/S0360-1315(14)00202-4/sref78http://refhub.elsevier.com/S0360-1315(14)00202-4/sref79http://refhub.elsevier.com/S0360-1315(14)00202-4/sref79http://refhub.elsevier.com/S0360-1315(14)00202-4/sref79http://refhub.elsevier.com/S0360-1315(14)00202-4/sref79http://refhub.elsevier.com/S0360-1315(14)00202-4/sref80http://refhub.elsevier.com/S0360-1315(14)00202-4/sref80http://refhub.elsevier.com/S0360-1315(14)00202-4/sref80http://refhub.elsevier.com/S0360-1315(14)00202-4/sref80http://refhub.elsevier.com/S0360-1315(14)00202-4/sref80http://refhub.elsevier.com/S0360-1315(14)00202-4/sref81http://refhub.elsevier.com/S0360-1315(14)00202-4/sref81http://refhub.elsevier.com/S0360-1315(14)00202-4/sref81http://refhub.elsevier.com/S0360-1315(14)00202-4/sref82http://refhub.elsevier.com/S0360-1315(14)00202-4/sref82http://refhub.elsevier.com/S0360-1315(14)00202-4/sref82http://refhub.elsevier.com/S0360-1315(14)00202-4/sref82http://refhub.elsevier.com/S0360-1315(14)00202-4/sref82http://refhub.elsevier.com/S0360-1315(14)00202-4/sref83http://refhub.elsevier.com/S0360-1315(14)00202-4/sref83http://refhub.elsevier.com/S0360-1315(14)00202-4/sref83http://refhub.elsevier.com/S0360-1315(14)00202-4/sref83http://refhub.elsevier.com/S0360-1315(14)00202-4/sref82http://refhub.elsevier.com/S0360-1315(14)00202-4/sref82http://refhub.elsevier.com/S0360-1315(14)00202-4/sref82http://refhub.elsevier.com/S0360-1315(14)00202-4/sref82http://refhub.elsevier.com/S0360-1315(14)00202-4/sref81http://refhub.elsevier.com/S0360-1315(14)00202-4/sref80http://refhub.elsevier.com/S0360-1315(14)00202-4/sref80http://refhub.elsevier.com/S0360-1315(14)00202-4/sref79http://refhub.elsevier.com/S0360-1315(14)00202-4/sref79http://refhub.elsevier.com/S0360-1315(14)00202-4/sref78http://refhub.elsevier.com/S0360-1315(14)00202-4/sref78http://refhub.elsevier.com/S0360-1315(14)00202-4/sref78http://refhub.elsevier.com/S0360-1315(14)00202-4/sref77http://refhub.elsevier.com/S0360-1315(14)00202-4/sref77http://refhub.elsevier.com/S0360-1315(14)00202-4/sref76http://refhub.elsevier.com/S0360-1315(14)00202-4/sref76http://refhub.elsevier.com/S0360-1315(14)00202-4/sref75http://refhub.elsevier.com/S0360-1315(14)00202-4/sref75http://refhub.elsevier.com