using computer animation and illustration activities to improve high school students'...

JOURNAL OF RESEARCH IN SCIENCE TEACHING VOL. 45, NO. 3, PP. 273–292 (2008)

Using Computer Animation and Illustration Activities to Improve High SchoolStudents’ Achievement in Molecular Genetics

Gili Marbach-Ad,1,2 Yosi Rotbain,1 Ruth Stavy1

1School of Education/Humanities, Tel Aviv University, Ramat-Aviv, Tel Aviv, Israel

2College of Chemical and Life Sciences, University of Maryland, 1328 Symons Hall,

College Park, Maryland 20742

Received 3 October 2006; Accepted 7 May 2007

Abstract: Our main goal in this study was to determine whether the use of computer animation and

illustration activities in high school can contribute to student achievement in molecular genetics. Three

comparable groups of eleventh- and twelfth-grade students participated: the control group (116 students)

was taught in the traditional lecture format, whereas the experimental groups received instructions that

integrated a computer animation (61 students) or illustration (71 students) activities. We used three research

instruments: a multiple-choice questionnaire; an open-ended, written questionnaire; and personal

interviews. Five of the multiple-choice questions were also given to students before they received their

genetics instruction (pretest). We found that students who participate in the experimental groups improved

their knowledge in molecular genetics compared with the control group. However, the open-ended

questions revealed that the computer animation activity was significantly more effective than the illustration

activity. On the basis of these findings, we conclude that it is advisable to use computer animations

in molecular genetics, especially when teaching about dynamic processes; however, engaging students

in illustration activities can still improve their achievement in comparison to traditional instruction.

� 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 273–292, 2008

Keywords: biology; achievement; attitudes

This study integrates two leading research areas in science education today: students’

understanding of molecular biology and the use of computers in science education. As for the first

research area, the rapid development of research in molecular biology in the last two decades and

its major implications for everyday life have had a major influence on high school curricula,

raising much interest in the investigation of students’ conceptions concerning molecular genetics

(e.g., Marbach-Ad, 2001; Bahar, Johnstone, & Sutcliffe, 1999; Garton, 1992; Golan & Reiser,

2002; Kindfield, 1994a,b). Recent studies (e.g., Golan & Reiser, 2002) on students’ understanding

of principles and concepts in molecular genetics suggest that current genetics instruction

Correspondence to: G. Marbach-Ad; E-mail: [email protected]

DOI 10.1002/tea.20222

Published online 5 December 2007 in Wiley InterScience (www.interscience.wiley.com).

� 2007 Wiley Periodicals, Inc.

leaves students unprepared to understand the everyday benefits and problems resulting from

technological advances in molecular genetics, such as genetic counseling, screening, and choices

(Lewis & Wood-Robinson, 2000). Furthermore, students are not informed enough to understand

and participate in current debates involving genetic issues, such as genetically modified foods,

cloning, and gene therapy (Garton, 1992).

For the second research area, the fast-growing use of personal computers in almost all

domains of life has also influenced science education. A number of science educators believe that

computer animation (also called computer simulation) in particular has tremendous potential for

the enhancement of the teaching and learning of science concepts (e.g., Ellis, 1984; Marks, 1982).

According to those researchers it is in the area of animations that computers have the potential to

deal with higher-learning outcomes in a way not previously possible inside the science classroom.

Educators and researchers have been commenting on the potential of using animations and

other software in genetics instruction to facilitate the visualization of abstract concepts and

processes at the micro level of instruction (Tsui & Treagust, 2004; Wu, Krajcik, & Soloway, 2001).

In fact, on the web we found a fairly large number of dynamic animations, including interactive

animations, illustrating either the molecular structures of DNA, RNA, and protein, or the

processes of DNA replication, transcription, and translation. However, the science education

literature has hardly any experiment-based reports about the effect of the use of computer

animation models on student achievement in molecular biology (Gearner, 2001; Hays, 2001).

The question whether computer animations are preferable to other classroom activities is still

unanswered. In our study we sought to examine the additional value of the computer animation

over illustration activities, and explored the impact of using these activities on students’

achievement in different subtopics (e.g., DNA and RNA structure and DNA replication,

transcription, and translation). This study specifically builds on our previous article published in

this journal (Rotbain, Marbach-Ad, & Stavy, 2006).

Theoretical Background

The molecular aspects of genetics gained central importance in the second half of the

twentieth century, with Watson and Crick’s discovery of the structure of DNA, an event that gave

rise to entirely new disciplines (e.g., genetic engineering) and influenced the direction of many

established ones (Nelson & Cox, 2000, p. 332). Garton (1992), referring to the difficulties of

genetics instruction in high school, argued that, as the revolution in the field of genetics continues,

the web of abstract concepts becomes increasingly complex.

In our earlier investigation (Rotbain et al., 2006) we elaborated on students’ difficulties in

understanding molecular genetics concepts and processes, and argued that these difficulties are

especially attributed to the emphasis on minute detail and abstract concepts (Malacinski & Zell,

1996). Researchers who take a constructivist approach to teaching recommend, in the face of such

difficulties, to enhance teaching through active engagement using models and visualization.

Educators agree that visualization and modeling constitute an important component in

science achievement generally (Gilbert, Justi, & Aksela, 2003), and on the molecular level in

particular. Graphics visualization tools such as molecular modeling and animation can be used to

give an accurate and rich picture of the dynamic nature of molecules and molecular interaction,

which is often very difficult to understand from text-based presentations of information (NSF,

2001).

The enthusiasm for graphics of all kinds rests on the belief that they benefit comprehension

and learning, and foster insight. Many advantages of graphics have been proposed. Graphics

provide an additional way of representing information: two codes, pictorial and verbal, are

274 MARBACH-AD, ROTBAIN, AND STAVY

Journal of Research in Science Teaching. DOI 10.1002/tea

better than one. Graphics may be aesthetically appealing or humorous, attracting attention and

maintaining motivation. Graphics use visual elements and the spatial relations among them to

represent elements and relations that may be visuospatial, or may be metaphorically visuospatial,

applying the power of spatial inference to other domains (Larkin & Simon, 1987; Tversky, Bauer

Morrisony, & Betrancourt, 2002). Graphics may save words by showing things that would

otherwise need many words to describe. Thus, another function of graphic displays is to use space

to organize information and to facilitate memory and inference. The benefit to the individual mind

is reducing the burden on memory and processing by off-loading.

Recently, with the advent of new technologies for instruction, an increasing reliance on

visuals in molecular-level instruction has come to include animated computerized graphics

(Lowe, 2003, p. 157). Animated computerized graphics are widely used in research for the same

reasons that they could be useful in education, namely to explore emergent behavior of systems

too complex for closed solutions and to follow the evolution of these systems. The ability to

visualize what happens to collections of interacting atoms and molecules under many different

conditions and rules gives the researcher a deep, intuitive understanding of the system under

study. Learning experiences based on molecular dynamics tools should help students develop

more scientifically accurate mental models of atomic- and molecular-scale phenomena, which

should in turn help them to reason more effectively at different levels, like experts (Pallant &

Tinker, 2004).

We believe that the phenomena and processes in the molecular genetics domain are likely to

be better understood with graphics and animations for several reasons. In what follows we

elaborate on these reasons, referring to the literature. It is noteworthy that most of the research on

using computerized models for molecular-level domains comes from chemistry (Barnea & Dori,

1996; Williamson & Abraham, 1995; Wu et al., 2000), whereas only a few studies deal specifically

with molecular biology (Pallant & Tinker, 2004; Tsui & Treagust, 2004).

The first reason why using graphics and animation benefits molecular biology instruction

concerns the need to understand the molecular structure and molecular/atomic interactions.

Hmelo, Holton, and Kolodner (2000) suggested that structures are often the easiest aspect of a

complex system to learn; in molecular genetics especially, understanding the structure of

molecules such as DNA and RNA is crucial to comprehending their functions. Graphics in this

case can help to organize the small pieces of information into large chunks of information,

reducing the amount of memorization required by increasing the logical connections between

ideas (Pallant & Tinker, 2004; Tversky et al., 2002).

Pallant and Tinker (2004) described the use of two molecular dynamics models (Molecular

Workbench and Pedagogica) embedded in a set of online learning activities with middle and high

school students in ten classrooms. Their studies found that middle and high school students can

acquire robust mental models of the states of matter through guided explorations of computational

models of matter based on molecular dynamics. Using this approach, students accurately recall

arrangements of the different states of matter, and can reason about atomic interactions. Follow-up

interviews indicate that students are able to transfer their understanding to new contexts.

Barnea and Dori (1996) suggested that the advantage of the computerized molecular model is

that, through the use of software, molecules of any size, number, and type can be conveniently

constructed, making the presentation more accurate. Barnea and Dori, exploring the effect of

using molecular modeling on tenth graders, also found that it helped students understand concepts

in molecular geometry and bonding.

Wu et al. (2000) investigated how students develop their understanding of chemical

representations with the aid of a visualizing tool, eChem, which allows them to build molecular

models and view multiple representations simultaneously. Multiple sources of data were

COMPUTER ILLUSTRATION AND ANIMATION 275


collected with the participation of 71 eleventh graders over a 6-week period. The results of the

pre- and posttests show that students’ understanding of chemical representations improved

substantially.

The second reason for using graphics and animation in molecular biology concerns the need

to understand dynamic molecular processing with multiple steps. Phenomena and processes in

the molecular genetics domain (e.g., DNA replication, transcription, and translation) occur on

a minute space scale, involving multiple and diverse entities. They also take place in multiple

locations throughout the cell. Researchers have suggested that instruction involving computer

animations can facilitate the development of students’ visualization skills and their abilities to

think about chemical processes at the molecular level in a stepwise fashion (Sanger, Brecheisen, &

Hynek, 2001; Williamson & Abraham, 1995), especially when the animation allows interactivity.

Clearly, interactivity, a factor known to facilitate learning, can help overcome difficulties in

perception and comprehension. Stopping, starting, and replaying an animation can allow

reinspection, focusing on specific parts and actions. Animations that allow close-ups, zooming,

alternative perspectives, and control of speed are even more likely to be facilitating (Tsui &

Treagust, 2004; Tversky et al., 2002).

Williamson and Abraham (1995), who explored the effect of computer animation on the

particulate mental model of college chemistry students, concluded that animations might help

increase conceptual understanding by prompting the formation of dynamic mental models of the

phenomena at hand. They also found that students who viewed only static visuals either formed

static mental models that failed to provide adequate understanding of the phenomena, or did not

manage to form any mental model for the particulate nature of matter, and were left with

macroscopic views of the phenomena.

The third reason is related to students’ motivation to study the molecular level. Many high

school biology students, especially those who do not study advanced chemistry, have difficulty

in understanding chemical formulas and they develop a ‘‘phobia’’ of biology subjects on the

molecular level (e.g., genetics and photosynthesis). Using computerized animation can reduce this

fear by turning the learning into a kind of game. Barnea and Dori (1996) reported that tenth graders

who used computerized models in chemistry enjoyed using them and their attitudes toward the

software were positive.

Nevertheless, alongside the advantages of the use of computer animations, it is important

to mention that there are still some reservations regarding the recent preference for using

computerized programs as the major learning tool for any subject matter. Furthermore,

the question of whether the dynamic visuals of computer animations are preferable to

illustration activities, when learning dynamic processes, is still unanswered (Gearner, 2001;

Hays, 2001).

On the face of it, animations would seem more appropriate when representing dynamic

processes, an argument that was raised by Lewalter (2003), who claimed that animations are

superior for the visualization of spatial constellations and dynamic processes. However, Lewalter

himself suspected that arrows and series of frames, which are quite conventional symbols for

motion, might be sufficient in some cases.

In a study on the attitudes of prospective high school mathematics teachers toward integrating

computers into their future classroom teaching, 94 teachers were asked to present pro and con

arguments that would influence their use of computers in future mathematics teaching (Hazzan,

2003). In didactic and cognitive terms, the teachers’ major concern was that learners may

progress without understanding previous stages. Most programs enable students to proceed in a

trial-and-error fashion and finish the practice without understanding the topic at hand. Another

cognitive argument for the lack of benefit of computer animations in science learning, raised by



Lowe (2003), refers to the excessive information processing demands this medium sometimes

makes on learners: ‘‘with some animations, learners may face higher levels of cognitive load than

would be expected for static alternatives’’ (Lowe, 2003, p. 158).

Given the aforementioned advantages and drawbacks of computer animations and illustration

activities in genetic instruction in general, and in instruction of dynamic processes in particular, in

our study, we examined differences between two comparable groups: one used computer

animation and the other used illustration activities. More specifically, we examined the differences

between the two groups in terms of the impact of using dynamic animations or illustration

activities on students’ understanding of dynamic processes (transcription translation and DNA

replication) versus students’ understanding of static configurations (the structure of DNA and

RNA molecules).

Therefore, we established three major goals:

1. To examine and compare the effect of individual activity with illustration and with

computer animation on students’ achievement in molecular genetics.

2. To examine and compare the effect of the illustration activity and the computer activity

on student achievement in different subtopics (of both a static and a dynamic nature).

3. To examine students’ feedback about the contribution of the model to their learning.

Method

The sample consisted of 248 Israeli students from 20 eleventh- and twelfth-grade classrooms

in suburban and urban areas, who were majoring in biology. Students’ socioeconomic level was

similarly distributed in each class, and thus we decided to assign students to the different

treatments according to their biology class session. To verify the comparability of the groups we

also used a pre-test. Because students received the computer animation and the illustration

activities as additional practice to their traditional learning, we decided to compare between the

following three groups. One group, the control group (116 students from eight classes), was taught

in the traditional lecture format. The teachers used blackboard and transparencies and guided the

students to read and answer questions in the textbook. The same textbook was used in all

comparison groups. The second group, the computer animation group (61 students from five

classes), received 4 hours of computer animation activities, and the third group, the illustration

group (71 students from seven classes), engaged in 4 hours of illustration activities. Students in all

groups received about 50 traditional learning hours of genetics instruction, including 20 hours of

molecular genetics. The activities, both with computer animation and illustration, were

incorporated into the 20 hours that were dedicated to molecular genetics instruction. In both

the experimental groups the students received short lecture explanations and then moved to

practice with the models, whereas in the traditional group the teachers concentrated more on

lectures until they thought that the students understood the material.

The illustration activity consisted of typical textbook illustrations and covered the structure of

DNA and RNA, DNA replication, and protein synthesis. (More details about this group have been

provided in the study by Rotbain et al. [2006].) The illustrations we used in connection with the

molecular structure of DNA and RNAwere mainly chemical formulas (see Appendix A), whereas

those used for subcellular processes (DNA replication, transcription, and translation) were more

schematic, representing the major components that are essential for understanding the processes.

Our drawing-based activity offers an active, student-centered approach based on illustrations

typically used in textbooks. We accompanied these illustrations with a set of instructions that were

written for this purpose. The activity includes hands-on tasks, such as drawing, painting, and figure



completion, while also integrating minds-on tasks, such as finding missing words and answering

guiding questions (see example in Appendix A). It is worth mentioning that, in most textbooks,

drawings and illustrations appear simply alongside the running text and students in traditional

classes usually are not required to do anything with them (e.g., draw, fill in, etc.).

The computer animation (Logal Molecular Biology) presents the same concepts as the

illustration activity, including the structure of DNA and RNA, DNA replication, and protein

synthesis. The animation reduces the complexity of the concepts and processes in molecular

genetics by enabling students to watch the dynamic processes as a whole or step by step, and to

participate in interactive activities, such as taking an active part in simulated DNA replication,

transcription, and translation processes. Figure 1 shows selected snapshots of four computerized

activities. The first activity (Figure 1A, the DNA structure activity) appears on the computer as a

static animation (which can be explored and manipulated by the user), whereas the other three

activities (Figure 1B–D), which deal with processes, are presented through dynamic interactive

animations. Each process can be rerun by the students, continuously or in step-by-step mode, and

can be stopped and continued whenever they wish. These three activities are also interactive.

Figure 1B and C represent activities in which students can manually add new compatible

Figure 1. Selected snapshots representing four computerized activities.



nucleotides to the growing chain of nucleic acid (DNA in Figure 1B and RNA in Figure 1C).

Students can also identify the tRNA–amino acid complex and match it with the compatible codon

in the mRNA molecule. Hence, to complete the activity correctly, both on the computer and in the

booklet, students have to select relevant information, organize the information, and integrate this

with their existing knowledge.

The instructions for operating the animation were adapted to the Israeli high school

curriculum. Students were asked to work alone; each student had their own computer and activity

booklet, but they were encouraged to discuss the material in pairs to enhance cooperative learning.

Students received detailed instructions on how to manipulate the animation.

The Activity—Instructions and Guiding Questions

The instructions, written specifically for the computer animation (see example in Figure 2),

were slightly modified for the illustration activity and included activities such as drawing,

Figure 2. Example of computer animation activity—the translation process.



painting, figure completion, and finding missing words (for an example of the illustration activity

see Rotbain et al. [2006]).

The computer animation and illustration activities were accompanied by the same set of

guiding questions. The guiding questions were designed to focus students’ attention on main

issues so as to help them select the relevant information and organize it coherently. The questions

asked students to explain what they did in the activity (see Figure 2, Question 9), to relate between

concepts and processes, to find regularities, to predict the next step in the process (see Figure 2,

Question 6b), and to draw conclusions based on having done the activity.

Research Instruments

In this study we used three reliable and valid questionnaires that were used in our previous

study (Rotbain et al., 2006): a multiple-choice, written questionnaire; an open-ended, written

questionnaire; and another open-ended questionnaire, which was used for personal interviews.

The students received the multiple-choice questionnaire only after they had filled out and handed

in their open-ended questionnaire; thus, the correct options in the multiple-choice questions

could not be used as hints for the answers to the open-ended questions. Both the multiple-choice

and the open-ended questionnaires were filled out by 248 students and, of these, 67 students

(computer animation—19; illustration—22; control—26), randomly selected, were personally

interviewed.

The multiple-choice written questionnaire, which included 13 questions (full copies of the

instruments are available from the authors), was given to the students after the molecular genetics

instruction (posttest). Five of these questions were also administered before students received

their genetics instruction (pretest). For the five pretest questions, we constructed a composite

score, which was used for analysis of variance (ANOVA) testing to verify that the groups were

comparable. Composite scores, calculated for the posttest, were used to compare between

the three groups using one-way analysis of covariance (ANCOVA) testing on two levels: the whole

questionnaire and groups of questions (related to same subtopic). In this analysis we used the

pretest scores as a covariant. Then we used paired comparisons, with modified the Bonferroni

correction, to identify the sources of significant differences.

The open-ended written questionnaire included ten questions (see Appendix B) and was given

to the students only after molecular genetic instruction (posttest). We ranked each response to be

able to create a score (between 0 and 100) for each student and calculate composite scores. Thus,

we could analyze differences among the three groups using ANCOVA on three levels: the whole

questionnaire; groups of questions (related to same subtopic, see later); and each question alone.

We used paired comparisons, with the modified Bonferroni correction, to identify the sources of

significant differences.

To evaluate students’ responses, we referred to the scientific literature (Nelson & Cox, 2000;

Suzuki, Griffith, Miller, Lewontin, & Gelbart, 1999). An example of a response considered a

complete answer to the question: What is the ‘‘genetic code’’? is: A triplet of nucleotides (or bases)

in the DNA or RNA molecules, which is translated into amino acid (or codes for amino acids or

construction of proteins).

To validate the categorization and the ranking schemes, a sample of the students’ answers was

also given to two researchers in science education and to two high school biology teachers who

were not connected to this study. The raters were blinded to the treatment. Each of them

analyzed and defined categories and subcategories independently, and their categories were

similar to ours.



The individual interviews, which were semistructured (each 30 minutes in duration), were

recorded by the second author and included two types of questions: four content questions (What is

DNA composed of? How is genetic information encoded? How are the proteins synthesized

according to the genetic code? How does DNA replicate) and three other questions, which directed

students to talk about their experience during the instruction and about the contribution of the

model to their learning. The author transcribed these interviews. We analyzed the transcript to find

major categories and calculated percentages for each category.

The questions in the three research instruments were grouped under three main categories of

subtopics:

1. Questions dealing with the structure of DNA and RNA.

2. Questions dealing with the molecular processes of replication, transcription, and

translation.

3. Questions whose answer should reflect students’ understanding of the conceptual

relationships between the genetic material (i.e., genes) and the product (i.e., proteins).

Results

We investigated students’ understanding of genetics in three different groups (computer

animation group, illustration group, and control group), using multiple-choice and open-ended

questionnaires as well as individual interviews. Comparison of the three groups’ pretests through

ANOVA testing revealed no significant differences among the groups (mean scores: control group,

35� 26; computer group, 32� 20, illustration group, 35� 17). Therefore, these groups could be

treated as comparable groups.

Table 1 shows the average scores that we calculated from students’ answers to the open-ended

and the multiple-choice questionnaires. Inspection of the average scores composed of the

responses to the multiple-choice questionnaire shows that, in two of the groups (computer and

illustration), the average scores were similar (74 and 70, respectively), whereas in the control

group the average score was lower (61).

Analysis of students’ answers to the open-ended questionnaire showed that, similar to the

findings from the multiple-choice questionnaire, both the average scores composed of the

responses to the open-ended questionnaire of the computer group and of the illustration group

(68 and 58, respectively) differed significantly from those of the control group (46). However, the

Table 1

Average scores and standard deviations (in parentheses) for the open-ended and the multiple-choice

questionnaires

Type ofQuestionnaire

Computer(N¼ 61)

Illustration(N¼ 71)

Control(N¼ 116) F Paired Comparisons

Multiple-choicequestionnaire

74 (19) 70 (21) 61 (21) 11.32b Computer/controlb

Illustration/controlb

Computer/illustrationOpen-ended

questionnaire68 (16) 58 (19) 46 (22) 32.23b Computer/controlb


Computer/illustrationa

ap< 0.01; bp< 0.001.



average score of the computer group was significantly higher than that of the illustration group in

this open-ended questionnaire. Thus, the open-ended questionnaire articulated differences

between the two experimental groups in favor of the computer group.

Analysis of Subtopics

As mentioned in the Method section, the questions in both questionnaires could be grouped

under three categories of subtopics:

1. The structure of DNA and RNA.

2. The molecular processes of DNA replication, transcription, and translation.

3. The conceptual relationships between genetic material and its products.

The first and the second subtopics refer to the contents that were reflected directly by the

activities (structures and processes), whereas the third subtopic refers to an overview of the

whole subject, asking students to explain the relationship between the genetic material and its

product (protein, trait). Thus, it seemed of interest to compare the achievements of the three

groups in terms of the three subtopics. Tables 2 and 3 show the composite scores regarding the

multiple-choice questionnaire and the open-ended questionnaire, calculated for each of the three

categories. In what follows we elaborate on each subtopic, offering some examples of students’

responses to the open-ended questions from the written questionnaire and from the individual

interviews.

1. The structure of DNA and RNA. A total of eight questions in the two questionnaires (four

questions each) were grouped under this subtopic (the structure of DNA and RNA). These

questions focused on: the structure of nucleotides; the nitrogen bases that pair between the two

strands of DNA (A-T, C-G) or between the DNA and the RNA strands (A-U, C-G); and on

comparison between DNA and RNA in terms of their components and structure.

Inspection of the average scores of the multiple-choice questions (Table 2) concerning

this subtopic shows that the average scores for the computer (81) and the illustration (77) groups

were similar, but significantly higher than the average score of the control group (69). The

same pattern occurred with the scores of the open-ended questions of this subtopic (Table 3),

in which there were no significant differences between the computer (82) and the illustration

Table 2

Average scores and standard deviations (in parentheses) for groups of questions related to the same

subtopic in the multiple-choice questionnaire

SubtopicComputer(N¼ 61)



DNA and RNA structure 81 (24) 77 (29) 69 (34) 4.23a Computer/controlb

Illustration/controla

Computer/illustrationTranscription and translation 63 (29) 54 (32) 43 (31) 8.83c Computer/controlc

Illustration/controla

Computer/illustrationThe relationships between

DNA and protein77 (21) 78 (24) 69 (25) 5.57b Computer/controla


Computer/illustration

ap< 0.05; bp< 0.01; cp< 0.001.



(76) groups, but both scores were significantly higher than the average score of the control

group (60).

In the individual interviews, students were asked to characterize the structure of DNA. Most

of the students (about two thirds) from all groups stated that DNA is a double helix or composed of

nucleotides. Differences among groups were evident, especially concerning the molecular level.

About 72% of the interviewees from each of the illustration and the computer groups referred to

the components of the nucleotides (deoxyribose, phosphate residue and the nitrogen base),

whereas only 19% of the interviewees from the control group referred to the components of the

nucleotides.

The findings that were gathered through the three research instruments (written

questionnaires and individual interviews) indicate that integration of the computer model or

illustration activity in the instruction of the structures of DNA and RNA molecules enhanced

students’ achievement in similar ways.

2. The molecular processes: DNA replication, transcription, and translation. A total of seven

questions in the two questionnaires were concerned with the molecular processes of replication,

transcription, and translation. These questions explored two aspects of students’ understanding:

the mechanism of the molecular processes and the sequence of the phases occurring in each of

the molecular processes. Inspection of the average scores in the multiple-choice questions

(Table 2) concerned with the molecular processes shows a similar pattern to the one found in the

first subtopic: the average scores for the computer (63) and the illustration (54) groups were

similar, but significantly higher than the average score of the control group (43). Interestingly,

the open-ended questions of this subtopic (Table 3) revealed differences among the three

groups: the average scores of the computer group (69) were higher than those of the illustration

group (56), and each of these scores were significantly higher than the average score of the control

group (40).

In the interviews concerning the processes of transcription and translation, students

were asked to answer the question: How are proteins synthesized according to the genetic code?

A complete answer should refer to both processes of transcription and translation. In all

groups a low percentage of students referred to both processes (computer—31%; illustration—

27%; control—15%). About one third of the students in all groups (computer—32%;

Table 3

Average scores and standard deviations (in parentheses) for groups of questions related to the same

subtopic in the open-ended questionnaire

SubtopicComputer(N¼ 61)



DNA and RNA structure 82 (13) 76 (20) 60 (25) 30.80b Computer/controlb


Computer/illustrationTranscription and translation 69 (24) 56 (30) 40 (29) 25.48c Computer/controlb


Computer/illustrationa

The relationships betweenDNA and protein

48 (24) 37 (25) 34 (26) 8.15c Computer/controlc

Illustration/controlComputer/illustrationb

ap< 0.01; bp< 0.001.



illustration—32%; control—31%) referred correctly to one of the processes (transcription or

translation).

Concerning the process of DNA replication, students’ responses to the question: How is DNA

replicated? showed major differences between the groups that received treatment (computer or

illustration) and the control group. Most of the students from the computer group (95%) and from

the illustration group (82%) correctly explained the semi-conservative mechanism of replication,

whereas only 42% of the students did so in the control group.

The findings concerning this subtopic show that achievement with regard to processes

was lower than with regard to structure, in all questionnaires, for all of the groups. Note that the

open-ended questions in this subtopic reveal that the students who studied with the computer

animation outscored those who studied with the illustration model.

3. Conceptual relationships between the genetic material and its products. Eight questions,

from both questionnaires, were concerned with this subtopic (conceptual relationships between

the genetic material and its products). Table 2 shows that, in the multiple-choice questionnaire, the

average scores for the computer (77) and the illustration (78) groups were similar, but significantly

higher than the average score of the control group (69). In this subtopic, the average scores of the

open-ended questions (Table 3) revealed that the computer group (48) scored higher than the

illustration group (37) and the control group (35); there were no significant differences between

the illustration and the control groups.

In the interviews students were asked to answer the question: How is the genetic information

in DNA coded? Completely correct answers should refer to the structural aspect of the genetic

code—three nucleotides (codon)—and to its functional aspect, which is the relationship between

the codon and the amino acid. Analysis of the responses showed that 79% of the interviewees from

the computer group and 73% from the illustration group referred to the nucleotide triplet or the

nucleotides sequence. For example, one student said, ‘‘There are triplets of nucleotides, each

triplet determining one amino acid.’’ Another student said: ‘‘. . .every three nucleotides are

compatible with one specific amino acid.’’ In the control group, only 46% of the interviewees

referred to triplets of nucleotides or to the relationship between the sequence of nucleotides and

amino acids.

A summary of the findings concerning this subtopic shows that the average scores on the

open-ended questionnaires were much lower than those on the multiple-choice questionnaire, for

all groups. It seems that it was easier for students to choose the correct answer to the multiple-

choice questions than to articulate correct responses to the open-ended questions.

Students’ Feedback About the Contribution of the Model to Their Learning

In the interviews, following the content questions, students were asked to reply to three

additional questions. The first question was: What did you visualize when you described the DNA

structure and the processes of DNA replication, transcription, and translation? In the computer

group, 95% of the 19 interviewees referred to the computer animation. One student said: ‘‘I

saw the DNA, how it was drawn on the computer, how the RNA was built according to the

DNA sequence, and then the RNA strand moved from the DNA to the cytoplasm and joined

the ribosome.’’ Another student referred to transcription and translation by saying: ‘‘On the

computer you see exactly how the processes [transcription and translation] occur, and then you can

translate everything into words.’’ In the illustration group, only 54% of the 22 interviewees

answered that they visualized the illustrations (‘‘I saw the illustrations from the booklet; In the

booklet that we received we were asked to complete figures, and thus put things in a more visual

way’’).



Another interview question was: Did the activity help you in gaining a better understanding of

the subject matter? All the interviewees from the computer and the illustration groups gave an

affirmative answer to this question. Interestingly, most of the interviewees from the computer

group (84%) reported that the activity represented the subject matter in a more concrete

manner, whereas those from the illustration group (90%) said that the activity helped them mainly

to organize and summarize the subject matter. For example, students from the computer

group said: ‘‘Yes, the computer animation helped me very much. It demonstrated the process,

since you can’t really see it’’; ‘‘It was like I could see it in front of my eyes, and so I could connect

between things’’; ‘‘When you see it as a computer animation, even if it is not exactly as the process

occurs in the cell, it is much easier to remember, to visualize the process in your head’’; and ‘‘It

helped me more than the lesson in the class, since I could run it over and over as many times as I

wanted, and I could also do it at different speeds.’’ Students from the illustration group mentioned

how abstract concepts become more concrete: ‘‘I think that the drawing activity really helped

me to understand the components of the DNA. It was much more concrete that way. The figures

and the illustrations were the best part, but also the questions and the sentence completion

activity.’’

The final question in the interviews was: Do you find molecular genetics more difficult

than other topics in biology? This question was designed to determine whether different

activities influenced students’ attitude toward the subject. Indeed, 58% of the interviewees in

the control group evaluated the course in molecular genetics as very difficult, as compared

with 38% from the computer group and 24% from the illustration group. The students’

explanations referred mainly to the multiplicity of new abstract concepts in molecular

biology, such as ‘‘. . .there are many concepts to remember, and when they all get mixed up in

your head it is very difficult to see the relationships between them’’ (student from the computer

group).

Students from the computer group also said that the activities ‘‘broke the routine’’ of the

traditional lecture format, and many commented that they enjoyed the activity very much and

would like to do more, in other biology topics as well.

Discussion

This study has focused on the use of computer animation and illustration activity in

molecular genetics instruction, a difficult topic for high school students (Rotbain et al., 2006). The

findings show that, overall, the students in the illustration group significantly improved

their knowledge compared with the students in the control group, in both the multiple-choice and

the open-ended questionnaires. The findings from the multiple-choice questionnaire also show

that there were no significant differences between the computer animation and the illustration

groups. However, the open-ended questionnaire did bring to light differences between these

groups, revealing that the computer animation was in general more effective than the illustration

activity. This bore out the unique impact of the computer animation model on students’

understanding.

In this investigation we also examined students’ achievements in three subtopics:

1. The structure of DNA and RNA.

2. The molecular processes: DNA replication, transcription, and translation.

3. The conceptual relationships between genetic material and its products.



Close inspection of the findings reveals interesting results concerning the contribution of

each model (illustration and computer animation) to students’ understanding of each of the

aforementioned subtopics.

The Structure of DNA and RNA

There were no significant differences between the illustration and the computer animation

groups in the multiple-choice and the open-ended questions that dealt with the DNA and the RNA

structures. Also, the scores for these questions were higher than the scores for the other two

subtopics. These results are consistent with the suggestion that structures are the easiest aspect of

a complex system to learn (Hmelo et al., 2000). However, we suspect that, in our case, the

reason could be that the illustration activity (see Appendix A), which explains the structure of the

DNA and RNA molecules, is not inferior to the parallel computer animation activity (see

Figure 1A). In the computer animation the students could point at different parts of the DNA

molecule and use a ‘‘magnifying glass’’ to watch the different structural levels, whereas in

the illustration activity the students had to identify (a higher cognitive level) the different

components and circle each component in different colors. Coloring the different components of

the DNA molecule in different shades (Appendix A) reduced the amount of information students

had to assimilate, and enhanced their understanding of the major structures of the complex DNA

molecule.

In our preliminary study, we found that it is difficult for high school students even to

discriminate between the three basic components of the nucleotides: sugar; the phosphate group;

and the nitrogenous bases. We therefore started the DNA structure activity by introducing

the nucleotide components, emphasizing their unique structures. In the illustration activity the

students were asked to identify and circle the components (sugar, the phosphate group, and

the nitrogenous bases) in each nucleotide’s chemical formula, and then to recognize and identify

the four nucleotides and the hydrogenous bonds in the chemical formula of the double-strand DNA

molecule (see activity in Appendix A). In the computer animation activity students were also

exposed to the different components of the nucleotide, and they could watch it over and over, but

they were not as active as in the illustration activity.

The contribution of the illustration activity to the understanding of the DNA structure was also

mentioned by the students in the interviews: ‘‘In the textbook I couldn’t understand the text and the

illustrations. . .while here, during the [illustration] activity, the coloring of the illustrations really

helped. . .that’s what helped me to understand the DNA structure and all its components. . ..’’ Other

advantages that students from both groups mentioned were that the active way of dealing with the

chemical formulas reduced their anxiety about such abstract forms of representation. As

mentioned in the Theoretical Background section, many high school biology students, especially

those who do not study advanced chemistry, have difficulty understanding chemical formulas and

they develop a ‘‘phobia’’ of biology subjects connected to the molecular level.

The Molecular Processes: DNA Replication, Transcription, and Translation

In contrast to the results concerning the DNA and RNA structure, there were significant

differences between the illustration and the computer animation groups regarding this subtopic,

which deals with dynamic processes. Answers coming from the computer animation group were

more accurate and profound than those from the illustration group. Thus, we believe that the



computer animation model offers a unique contribution to the understanding of the dynamic

subcellular processes of replication, transcription, and translation. It is noteworthy that, in the

computer animation activities, which deal with the processes of replication, transcription, and

translation, students could run and watch the different steps over and over (Figures 1 and 2); they

were involved in the virtual building of the molecules and, overall, were more active than students

who used the illustration activity. Clearly, interactivity, a factor known to facilitate learning, can

help overcome the difficulties of perception and comprehension. Stopping, starting, and replaying

an animation can allow reinspection, focusing on specific parts and actions. Animations that allow

close-ups, zooming, alternative perspectives, and control of speed are even more likely to facilitate

perception and comprehension (Tversky et al., 2002).

The contributions of the computer animation’s interactivity as well as the immediate feedback

were mentioned by the students in the interviews: ‘‘I actually built the RNA strand according to the

DNA strand and if I made a mistake the computer didn’t let me go on, so I didn’t need the teacher

around to correct me; I could change the nucleotide sequence and immediately watch the impact of

my manipulations on the amino acid chain.’’

Our findings concerning the superiority of the computer animation activities over the

illustration activities in terms of learning the molecular processes also accord with Williamson and

Abraham (1995), who explored the effect of computer animations on college chemistry students,

and found that instruction with animations may increase conceptual understanding by prompting

the formation of dynamic mental models.

The Conceptual Relationships Between Genetic Material and Its Products

Regarding this topic—the conceptual global understanding of the flow of information from

genetic material to the phenotypic product—the findings show that both the illustration and the

computer animation groups scored low, particularly in the open-ended questions. The computer

animation group outscored the illustration group (48% and 37%, respectively), but the score was

still rather low. It seems that the computer animation activity helped students to better understand

each of the processes (DNA replication, transcription, and translation), but was less useful in

explaining the global idea (the central dogma) of how DNA molecule codes for protein and hence

for traits. We suspect that part of the explanation for these results is that students need time to

assimilate the whole idea of the central dogma, and be able to make the synthesis between the

different processes involved (transcription and translation). It appears that one of the reasons

genetics is so difficult both to teach and to learn derives from the fact that students must be able to

integrate several cognitive steps in order to understand the processes underlying genetic

phenomena and to grasp the overall picture of genetics (Fisher, 1983).

We believe that supplemental computerized animation activities can help students gain a

better understanding of the global concept of the flow of information from genetic material to

phenotypic product. Such activities should enable the students to be actively engaged in

manipulating the DNA sequence (i.e., causing mutations) and tracking the changes in the product,

following the DNA changes (protein or trait).

Conclusions and Implications

This study has explored the effect of computer animation and illustration activities on high

school student achievement in molecular genetics. In doing so it integrates the two leading



research areas in science education today: students’ understanding of molecular biology and the

use of computers in science education. Our results confirm the idea that proper use of technology

can enhance students’ achievement in molecular biology, which encourages wide-ranging

educational research on approaches to teaching scientific topics with new technologies, such as

computer animations.

Our findings specifically show that computer animations work, especially in teaching

about dynamic processes; however, engaging students in illustration activities (especially when

learning about the DNA structure) also improves achievement in comparison to traditional

instruction only.

These findings raise questions about the deep difference between the computer animation and

the illustration activities. We found that, although the computerized activities have enormous and

increasing potential as learning tools, illustration activities are not necessarily inferior to them,

and each model has its strengths and weaknesses: When we decide to use a certain model we

should make sure that it is the best model for the specific activity. Close inspection of the model

activities showed us that the illustration activity for the DNA structure allowed students to be more

interactive and less passive than in the parallel computer activity. In contrast, the computer

animation activities that demonstrate the dynamic processes allowed students to be more

interactive, learn from trial and error, and repeat their trial over and over—none of which were

possible with the illustration activity.

This also brings to light the importance of engaging students in an interactive way. The most

straightforward suggestion for using visualization effectively is to make visualization interactive

and increase active student involvement in learning. These recommendations are in accord with

the educational practice reforms advocated by the major professional science education

communities (AAAS, 1993; NRC, 1996).

We believe that our study offers evidence for the promising potential of using models in

biology topics at the molecular level (molecular genetics, photosynthesis, and cell respiration) as

well. In a previous study we reported on the success of using a tri-dimensional bead model and an

illustration model in the study of molecular biology (Rotbain et al., 2006); the current study adds

new findings to our earlier article by presenting the strengths and weaknesses of a computer

animation model in teaching molecular biology.

Recommendations for Further Study

We consider this study as the groundwork for many future studies. It is hoped that we and

others can:

1. Use the models and the research instruments from this study to measure students’

understanding, while taking into consideration students’ previous knowledge and

cognitive level (e.g., differentiate between top, middle, and low achievers), thus

providing ways to build on students’ personal understanding of science.

2. Examine whether enhancement of the model interactivity could improve

student achievement. For example, in our research we felt that the computer

animation structure activity could be improved to be more interactive and thought-

provoking.

3. Articulate the differences between the three models that we used—illustration,

computer animation, and three-dimensional bead model (Rotbain et al., 2006)—in a

way that will give us information on how to integrate between the different types of

models, matching the characteristics of the model to the characteristics of the specific

topic or subtopic (i.e., static versus dynamic or structure versus processes).



The authors gratefully acknowledge Yftach Gordoni for statistical analysis and

Mirjam Hadar for editing, both of whom are at the School of Education, Tel-Aviv

University.

Appendix A

Example of an illustration activity (Rotbain et al., 2006):



Appendix B

The average scores and standard deviations (in parentheses) of the experimental and control

groups for each of the open-ended questions and F values:

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Subtopic Questions

Average Scores

FComputer(N¼ 61)


Control(N¼ 116)

DNA and RNAstructure

1. What is DNA? 77 (20) 66 (26) 65 (25) 5.03a

2. Write a sentence thatincludes the conceptsnucleotide and nitrogenbase.

94 (18) 81 (32) 60 (44) 20.49b

3. Complete the followingsentences:(a) The four nucleotides

of DNA have incommon. . ..

79 (30) 79 (32) 46 (41) 27.89b

(b) The differences betweenthe four nucleotides ofDNA are due to. . ..

4. Is information about thesequence of one strandsof DNA sufficient todetermine the sequence ofthe other strand?

79 (25) 78 (24) 68 (29) 5.28a

Transcription andtranslation

5. How does DNA replicationoccur in the cell?

79 (31) 58 (44) 40 (44) 19.87b

8. Can the translation processoccur without thetranscription process?Explain your answer.

72 (33) 67 (32) 44 (33) 20.31b

9. Can protein synthesisoccur without the presenceof t-RNA? Explain youranswer.

57 (33) 43 (35) 37 (33) 25.16b

The relationshipsbetween DNAand protein

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63 (35) 49 (39) 41 (41) 7.58a

7. What is the genetic code? 44 (29) 31 (23) 32 (32) 4.3510. You were asked to design a

gene that codes for insulin.Which information do youneed in order to do it?Explain your answer.

38 (40) 32 (37) 29 (36) 1.32

ap< 0.05; bp< 0.001.



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