improving your creative potential without awareness: overinclusive thinking training
TRANSCRIPT
Accepted Manuscript
Title: Improving Your Creative Potential without Awareness:Overinclusive Thinking Training
Author: Fa-Chung Chiu
PII: S1871-1871(14)00056-XDOI: http://dx.doi.org/doi:10.1016/j.tsc.2014.11.001Reference: TSC 275
To appear in: Thinking Skills and Creativity
Received date: 25-1-2014Revised date: 30-7-2014Accepted date: 9-11-2014
Please cite this article as: Chiu, F.-C.,Improving Your Creative Potential withoutAwareness: Overinclusive Thinking Training, Thinking Skills and Creativity (2014),http://dx.doi.org/10.1016/j.tsc.2014.11.001
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Improving Your Creative Potential without Awareness: Overinclusive Thinking Training
Fa-Chung Chiu*
Department of Psychology and Social Work, National Defense University, 112, Taiwan
(R.O.C.)
E-mail addresses:
*Corresponding author. Tel.: +886 2 2892 9194 ext.12; fax: +886 2 2891-4169
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Highlights
>We manipulate the overinclusive thinking training and measure participants’ performance in
creativity. >We examine the effects of the overinclusive thinking training on creativity
improvement. > The complete overinclusive thinking training can improve creativity.
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ABSTRACT
The purpose of this study was to examine the effects of overinclusive thinking training (OTT)
on creativity improvement. In Experiment 1, 40 undergraduates were randomly assigned to
the OTT group or the control group. After the training, the participants were required to
complete categorization tasks. The results show that the OTT enhanced participants’ ability to
engage in overinclusive thinking. In Experiment 2, 42 undergraduates were randomly
assigned to the OTT group or the control group. After the training, the participants were
required to complete the Creative Thinking Test. The results show that the performance of the
OTT group regarding fluency and originality was higher than that of the control group. In
Experiment 3, 56 undergraduates were randomly assigned to three groups: the control group,
the long-distance semantic OTT group, or the short-distance semantic OTT group. After the
training, the participants were required to solve insight problems. The results show that the
performance of the long-distance semantic OTT group in insight problem solving was
superior to that of the short-distance semantic OTT and the control group. In Experiment 4,
50 undergraduates were randomly assigned to the OTT group or the control group. The
Creative Thinking Test was performed 7 days after training. The results show that the training
effect on originality remained; however, no training effect was observed on either fluency or
flexibility.
Keywords: creativity, divergent thinking, insight problems, overinclusive thinking training
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1. Introduction
In a knowledge-based economy, creativity is considered a core indicator of the
competitiveness of countries, organizations, and people (Egan, 2005).Creativity is an
essential part of organizational innovation (Amabile & Khaire, 2008). In addition, it helps
people manage social conflicts and disputes (De Dreu, Baas, & Nijstad, 2008). Therefore,
improving creativity has become a critical concern; specifically, how people generate creative
ideas and solutions has attracted considerable attention from scholars (Roskes, De Dreu, &
Nijstad, 2012). For improving creativity studies, numerous researchers have developed
methods to improve creativity (e.g., Cheng, Wang, Liu, & Chen, 2010; Chiu, 2012, 2014;
Chiu &Tu, 2014; Chrysikou, 2006; Fleith, Renzulli, & Westberg, 2002; Koppel & Storm,
2013; Lewis & Lovatt, 2013; Nusbaum, Silvia, & Beaty, 2014; Oppezzo & Schwartz, 2014;
Patrick & Ahmed, 2014).
In the past, most of the creativity training methods were categorized as explicit creative
skills because the purpose of the training was to teach participants to apply creative skills
consciously to enhance creativity. However, occasionally, using creative skills did not
improve creativity because consciously applying creative thinking skills might interrupt the
search for creative answers and further hinder creative thinking (Zhong, Dijksterhuis, &
Galinsky, 2008). In addition, although explicit creative skills (rule-based training) could
provide new thinking directions, remote association ability is still required to be able to
associate unrelated concepts and subsequently generate original and creative ideas. If the
association between one person’s remote knowledge nodes is weak, the effect of explicit
skills would not be significant. For example, when asking participants with a weak
knowledge node connection to perform free association, despite their ability to use creative
skills consciously, they are not able to generate creative ideas or products; for example,
people who experience difficulty in connecting houses and chopsticks are not able to imagine
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that a house could be built with chopsticks.
To overcome these limitations, developing non-rule-based training of creative thinking,
which could directly strengthen the connections between knowledge nodes in the human
brain, is necessary. The purpose of this study was to develop non-rule-based training methods
based on Eysenck’s theory of overinclusive thinking (Eysenck, 1995).
1.1 Creativity
Generally, regarding the characteristics of created products, creativity has been defined
as the ability to develop novel and appropriate ideas (Sternberg & Lubart, 1999). A novel
creative product refers to a product or idea that has never appeared before or has never been
applied in a certain manner. Regarding the characteristics of the creative process, creativity is
considered as a process involving knowledge activation (Eysenck, 1995), remote association
(Mednick, 1962), divergent thinking (Guilford, 1957), and insight ability (Mayer, 1995).
Scholars have commonly adopted creative thinking tests, including the divergent thinking test
(Guilford, 1957), insight problems (Schooler & Melcher, 1995), the remote association test
(Mednick, 1962), the creative generation task (Friedman & Förster, 2002), and the
dominance-to-rank ratio (Leung & Chiu, 2010), to measure creative potential and
differentiate people with high and low creativity. In this study, the divergent thinking test
(Guilford, 1957) and insight problems were used to measure the participants’ creative
potential. Divergent thinking is defined as the ability to produce numerous diverse creative
ideas (Guilford, 1956). Guilford (1956) developed an alternative uses test that can be used to
examine participants’ divergent thinking and includes fluency, originality, and flexibility
indices. Fluency refers to the ability to create substantial number of ideas, originality refers to
the ability to generate novel ideas, and flexibility refers to the ability to produce multiple
conceptual categories. Regarding insight problems, Dominowski (1995) stated that “problem
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solvers usually encounter obstacles at first, then later invent a sudden ‘a-ha!’ solution.” An
example of this is the candle problem (Duncker, 1945; details are provided in Section 3.1.2
Materials).
The advantage of the divergent thinking test is that it can be used to measure divergent
thinking responses (Runco, 1999). However, divergent thinking tests do not include specific
solution objectives; consequently, solution appropriateness is not considered (Lin, Lien, &
Jen, 2005). To overcome the disadvantage of divergent thinking tests in that they do not
emphasize response appropriateness, we used insight problems that focus on solution
appropriateness to measure creativity (i.e., creative insight problems combine divergent
elements with convergent elements [De Dreu, Nijstad, Baas, Wolsink, & Roskes, 2012]).
Moreover, if consistent results are obtained from various creative measurement tools, the
robustness of the research outcome can be enhanced.
1.2 Overinclusive Thinking Training
According to Scott, Leritz, and Mumford (2004), the results of meta-analysis regarding
the effectiveness of creativity training revealed that the effective instruction of creative skills
or rules is a core factor of effective creativity training. Several explicit skills for creativity
improvement have been proposed, such as the association skill (Cheng et al., 2010; Gruszka
& Necka, 2002; Piers & Morgan, 1973), creative problem solving (Parnes, 1962), cognitive
stimulation (Fink et al., 2010), divergent thinking (Fleith et al., 2002; Runco, 1991),
conceptual combination (Kohn, Paulus, &Korde, 2011), Synectics (Gordon, 1961); future
thinking (Chiu, 2012); instruction on how to be creative (Nusbaum et al., 2014),
improvisation (Lewis & Lovatt, 2013), and representation change (Patrick & Ahmed, 2014).
These creative skills provide rules for participants to apply to perform creative thinking.
For example, by using association skills, participants can associate two ideas to create novel
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products (Cheng et al., 2010). An example of this application is the association between
vehicles and houses, which results in the creation of mobile homes. Thus, when people apply
these creativity skills, they are in a state of controllable consciousness and awareness
(Dorfman, Shames, & Kihlstrom, 1996). However, consciously using explicit creative skills
might hinder the search for new ideas (Zhong et al., 2008). Zhong et al. (2008) found that in a
state of unconscious thought, participants were distracted when taking the Remote Associates
Test (RAT). Compared with the state of conscious thought (not including distracter tasks),
the state of unconscious thought increased the accessibility of RAT answers, indicating that
when participants are searching strategies to achieve problem-solving objectives, creativity
performance may be hampered.
From the perspective of working memory (WM), when a person engages in two
cognitive activities simultaneously, the performance of WM in conducting the main activity
diminishes (Lorist, Boksem, & Ridderinkhof, 2005). Retaining novel information in creative
thinking and discriminating between task-relevant and task-irrelevant information are two
crucial WM processes (Unsworth & Engle, 2007); therefore, WM capacity is essential to
creative thinking. The empirical study conducted by De Dreu et al.(2012) reported that when
participants were asked to complete each RAT item, they were also asked to remember two
(low load) or five (high load) digit strings. After completing the RAT items, the participants
were required to recall all the strings. The results indicated that participants under low-load
conditions performed more favorably than did those under high-load conditions. According to
the results, the wider the WM span is, the higher the creativity performance is. Therefore,
when people use rule-based (e.g., association skills) strategies to perform creative thinking,
rule operation may occupy WM capacity and prevent them from retrieving novel information
from the WM and applying task-related information. Thus, rule-based strategies hamper
creative thinking. To overcome the limitations of rule-based creative skills, developing
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non-rule-based creative training methods is necessary. In the following sections, we discuss
the possibility of non-rule-based creative training from an overinclusive thinking perspective.
The concept of overinclusive thinking was first proposed by Cameron (1944) to describe
the thinking pattern of schizophrenic patients. Overinclusive thinking is regarded as a
personality trait. Generally, overinclusive thinking is defined as the inability to preserve
conceptual boundaries (Andreasen & Powers, 1974); thus, people who engage in
overinclusive thinking have a broader conceptual framework. In addition, overinclusive
thinking can be described as increased generalization (Eysenck, 1993, 1995). When
completing the questions related to the categorization inclusion task, such as “Is a camel a
vehicle?”, overinclusive thinkers generally conclude that a camel is a vehicle based on its
similarity to cars or buses in that they are used to transport people or objects from one
location to another, whereas non-overinclusive thinkers generally exclude camels from the
vehicle category because they consider wheels to be a necessary feature of vehicles
(Friedman & Förster, 2002). Individuals who possess the overinclusive thinking trait are
highly capable of freeing their minds from conceptual boundaries, improving their creativity
by considering concepts that other people deem unrelated to certain categories, and thereby
providing an increased number of options (Campbell, 1960). Moreover, people with loose
and extensive associative networks are highly capable of performing divergent thinking and
generating highly original ideas (Eysenck, 2003).The empirical results of a previous study
indicated that participants with high psychoticism who exhibited the trait of overinclusive
thinking demonstrated superior originality in conceptual expansion and creative imagery than
participants with low psychoticism did (Abraham, Windmann, Daum, & Güntürkün, 2005).
Additionally, Andreasen and Powers (1975) discovered that creative writers generally exhibit
relatively strong overinclusive thinking. In summary, overinclusive thinking is correlated to
creativity.
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These relevant studies have indicated that although overinclusive thinking is considered
as a trait, this type of cognitive pattern can increase creativity through manipulation.
Chrysikou (2006) requested participants to complete the Alternative Categories Task (ACT)
in an experimental study. The participants were presented with 12 common items (e.g., shoes
and forks) and were asked to describe the common uses of the presented items. For example,
for shoes, the common category was an item used as footwear. In this task, the participants
were asked to describe the category of each item as specifically as possible. For example, a
shoe could also be an object used to pound a nail into a wall. When the participants
completed the ACT, they were asked to solve seven insight problems. The results indicated
that compared with the control group, the ACT group exhibited superior performance in
insight problem solving. The researcher asked the participants in the ACT group to propose
unusual uses for the items. Although Chrysikou did not state that the ACT was used for
overinclusive thinking training (OTT), this activity was similar to those involving
overinclusive thinking. For example, the participants included shoes in the category of
hammers, which represents the cognitive attribute of overinclusive thinking. Wen, Butler, and
Koutstaal (2013) also reported that participants who completed the ACT tasks improved their
performance in insight problem solving. Based on these relevant empirical studies, we
inferred that enhancing creativity training by using an overinclusive thinking perspective is
possible.
The concept of overinclusive thinking can also be explained by the spreading activation
theory proposed by Collins and Loftus (1975). Collins and Loftus indicated that semantic
memory nodes (e.g., as in birds) connect with each other and become conceptual networks
(e.g., an animal conceptual network). Hence, the activation of nodes in a network may spread
to related nodes or concepts. Semantic nodes from the same conceptual network possess a
strong association (e.g., cats and dogs, both are common domestic animals); by contrast,
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semantic nodes from different conceptual networks possess a weak association (e.g., cats and
the ocean). The spreading activation theory has been supported by empirical studies that
employed the semantic priming paradigm (Copland et al., 2003; Meyer & Schvaneveldt,
1971).
People with high creativity appear to be highly capable of spreading activation among
various conceptual networks. For example, creative people can generate the idea that fruit
and vehicles share common characteristics. In an empirical study, Rychlicka (cited in Necka,
1994) instructed participants to assess whether two words were associated. In the experiment,
half of the word pairs were closely associated (e.g., chair and table) and the other half were
remotely associated (e.g., chair and lawn). The results indicated that the semantic distance
between the word pairs influenced the participants’ judgments. For paired words with a short
semantic distance, the participants exhibited a significantly higher tendency to consider the
words as being related to each other. In addition, compared with participants with lower
creativity, highly creative participants generally considered paired words with a substantial
semantic distance as being related to each other. The ability to associate paired words with
long semantic distance is similar to the characteristic of overinclusive thinking; namely, it is
less likely to be limited by semantic conceptual boundaries and it facilitates the spread of
node activation throughout various conceptual networks. In addition, in an empirical study,
Mednick (1962) used the RAT to measure participants’ remote association capacity (e.g.,
question: rat, blue, and cottage; answer: cheese). The results suggested that individuals who
exhibited high ability in conducting remote association had high flexibility. Other studies
have also emphasized the relationship between remote association abilities and creativity (Cai,
Mednick, Harrison, Kanady, & Mednick, 2009; Vul & Pashler, 2007; Ward, Thompson-Lake,
Ely, & Kaminski, 2008). Therefore, participants with high creativity have a wide range of
conceptual nodes and can connect seemingly unrelated concepts.
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The aforementioned studies demonstrate that overinclusive thinking improves creative
performance. However, Chrysikou (2006) and Wen et al. (2013) requested participants to
classify items into untypical categories. This type of training requires participants to classify
an item into a certain category through active thinking; however, this type of training is
negatively affected by people’s existing knowledge structure. To avoid such an effect, the
OTT developed in this study does not require individuals to think. The proposed method only
requires individuals to classify irrelevant items passively into one category. For example, the
unrelated items, watch and paper, were classified into a category. This procedure of
classifying unrelated items into a category loosens the boundaries of knowledge concept
categories (Andreasen & Powers, 1974) and develops people’s ability to engage in
overinclusive thinking. Thus, the training effect of the method proposed in this study is not
limited by the existing overinclusive thinking capacity of people; instead, it is determined by
training materials and procedures.
OTT simply requires participants to classify items. In addition to participants not being
able to perceive training purposes during OTT, participants are not required to learn creative
rules (i.e., non-rule-based training), which is different from previous creative skill training
(e.g., Fleith et al., 2002; Patrick & Ahmed, 2014; Kohn et al., 2011; Runco, 1991). Thus, the
situation in which creativity performance is reduced because rule-based creative thinking
hampers WM operative performance can be avoided. The Experiment 1 section further details
the OTT procedure.
2. Experiment 1
Based on the hypothesis that overinclusive thinking improves creativity, we aimed to
improve participants’ creativity by conducting OTT. In this study, for example, the
participants were asked to press the “left” keyboard when words related to furniture (e.g.,
chair) or fruit (e.g., strawberry) appeared on the screen. They were asked to press the “right”
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keyboard when words related to housing space (e.g., bedroom) or vegetables (e.g., celery)
appeared on the screen. Although “bedroom” and “vegetables” belong to two unrelated
conceptual categories, the participants were trained to place “bedroom” and “celery” in the
same category (i.e., the right keyboard) during the OTT. In other words, OTT enabled the
participants to ignore existing knowledge categories and classify seemingly unrelated
exemplars into the same category, thereby expanding the inclusivity or scope of their
conceptual networks. Through this training, the participants’ overinclusive thinking could be
enhanced and their conceptual boundaries could be loosened. This resulted in improved
creativity and the improved ability to associate novel knowledge nodes after the training.
Experiment 1 was conducted to explore whether OTT could improve the participants’
overinclusive thinking. When the results of Experiment 1 verified that OTT improved
overinclusive thinking, the manipulation training task was confirmed to conform to the
argument (i.e., OTT improved overinclusive thinking) in the literature. Subsequently, we
explored how OTT enhances creativity in Experiments 2–4.
Experiment 1 was a one-factor between-subject design. The independent variable was
the group (i.e., the OTT group and the control group), and the dependent variable was the
participants’ performance in conducting the categorization task. Because conceptual
boundaries cannot be maintained during overinclusive thinking (Andreasen & Powers, 1974),
when people with high overinclusive thinking ability were requested to evaluate several
exemplars in the prototypical category, they generally classified nontypical and typical
exemplars into the same category (e.g., categorizing handbags as apparel). Individuals with
high overinclusive thinking ability perceive relatively ambiguous boundaries among
categories; therefore, they demonstrate increased category inclusiveness, which is the
characteristic of overinclusive thinking. In this study, overinclusive thinking was measured
using the categorization task (Isen & Daubman, 1984). The purpose of using the task was to
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observe how participants evaluate the category of non-typical exemplars. If the participants
exhibited a high tendency to classify non-typical exemplars into a typical concept category,
they were considered to demonstrate a high level of overinclusive thinking.
2.1 Method
2.1.1 Participants
A total of 40 undergraduates (29 men and 11 women) at the National Defense University
in Taiwan were recruited in Experiment 1. The mean of their ages was 20.01 years with a
standard deviation (SD) of 1.08. After eliminating one participant’s data because his training
accuracy was lower than 70%, the data of the remaining 39 participants were used in
statistical analyses.
2.1.2 Materials
2.1.2.1 Overinclusive Thinking Training Task
The purpose of developing the OTT task was to improve the participants’ overinclusive
thinking. In this task, the participants were asked to categorize exemplars of fruit (e.g.,
strawberry), vegetables (e.g., celery), furniture (e.g., chair), and housing space (e.g.,
bedroom), with 10 words in each category. These exemplars were selected from those
provided by Chiu (2010). SuperLab Pro 4.01 was employed to design this experimental task
and the training was conducted using computers (Fig. 1, Part A). Two labels (i.e., “left” and
“right”) were pasted on two keyboards that indicated the left and right keyboards, which the
participants used to make responses. The OTT task consisted of four blocks, with 120 trials in
each block. In the first and second blocks, during the beginning of each trial, a fixation point,
“+,” appeared for 500 ms on the screen to inform the participants that the stimuli would soon
appear. Subsequently, the participants pressed the “left” keyboard (the category label
appeared in the upper-left corner of the screen) when the exemplars belonging to the fruit or
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furniture category appeared (the word size was 4 cm in length and width). The participants
pressed the “right” keyboard when the exemplars belonging to the vegetable or housing space
category appeared (the category label appeared in the upper-right corner of the screen). The
only difference between the trials in the third and fourth blocks and those in the first and
second blocks was the keyboard used to provide a response. The participants was required to
press the “left” keyboard instead of the “right” keyboard when the exemplars belonging to the
vegetable or housing space category appeared, whereas they were required to press the
“right” keyboard instead of the “left” keyboard when the exemplars belonging to the fruit or
furniture category appeared. Six practice trials in which feedback was obtained were
conducted before formal training was provided. After confirming that the participants
understood the experimental procedure, formal training was conducted. In addition, a break
that lasted 3 min at most was allowed between each block.
+ strawberry
Fixation
fruit or furniture
vegetable orhousingspaces
500 ms Press the “left” or
“right”keyboard(s elf-paced)
ISI
Next Trial500 ms
Part A
Part B
Discrimination Task
+ strawberry
housingspaces
vegetable
Figure 1. OTT task procedures. Part A is the procedure used in each trial in the OTT task (e.g.,
Blocks 1 and 2); Part B is the procedure used in each trial for the control group (e.g., Block1).
Fixation is the cue used to remind the participants to begin the Discrimination Task. In the
Discrimination Task, the participants were asked to categorize the exemplars and respond by
pressing keyboards. ISI is the inter stimulus interval.
Regarding the training provided for the control group (Fig. 1, Part B), the participants
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were asked to categorize the exemplars belonging to the fruit, vegetable, furniture, and
housing space categories. However, the rules for categorization were different from those
used in the OTT task. In the first block, the participants were instructed to press the “left”
keyboard when an exemplar from the housing space category appeared and the “right”
keyboard when an exemplar from the vegetable category appeared. In the second block, they
were asked to press the “left” keyboard when an exemplar from the furniture category
appeared and the “right” keyboard when an exemplar from the fruit category appeared. In the
third block, they were asked to press the “left” keyboard when an exemplar from the
vegetable category appeared and the “right” keyboard when an exemplar from the housing
space category appeared. In the fourth block, the participants were instructed to press the
“left” keyboard when an exemplar from the fruit category appeared and the “right” keyboard
when an exemplar from the furniture category appeared. Participants in both groups
completed trials with identical exemplars in approximately 20 min (including breaks).
In summary, for the OTT task, the exemplars from two categories (e.g., the vegetable
and the housing space categories) were combined into one category (e.g., the “right”
keyboard), whereas the control group task required the participants to simply place exemplars
from the same category into one category. The OTT task was conducted to train the
participants in overinclusive thinking, whereas the control group task did not produce any
training effect.
2.1.2.2 Categorization Task
To measure overinclusive thinking, a categorization task (Isen & Daubman, 1984) was
employed and revised by applying typical and nontypical exemplars of clothing and vehicles
as stimuli in the task (Rosch, 1975). Three typical and three non-typical exemplars were
included in each category. Typical exemplars of the clothing category included suit, shirt, and
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pants, and non-typical exemplars included ring, purse, and cane; typical exemplars of the
vehicle category included train, automobile, and bus, and the non-typical exemplars included
camel, feet, and elevator. The participants were instructed to rate the exemplars on a 10-point
Likert scale, in which 1 indicated definitely does not belong to the clothing (or vehicle)
category and 10 indicated definitely belongs to the clothing (or vehicle) category. The scale
assumed that people who demonstrate overinclusive thinking exhibit loose conceptual
boundaries (Andreasen & Powers, 1974) and high flexibility; therefore, they would classify
the non-typical clothing exemplars as clothes. Participants’ overinclusive thinking was scored
according to the sum of the typicality rating of the non-typical exemplars of clothing and
vehicles. People with a high score exhibited a high level of overinclusive thinking. The
typical exemplars were used as a reference. The scoring of the typical exemplars was
identical to that of the non-typical exemplars.
2.1.3 Procedures
First, the participants were randomly assigned to the OTT group or the control group.
The first stage of the experiment was the training session. Following the training, the
participants were asked to complete the categorization task. At the end of the experiment, the
purpose of the experiment was explained and a NT$50 coupon was given as a token of
gratitude.
2.2 Results and Discussion
2.2.1 Accuracy Rates of the Training Task
Data with accuracy below 70% were deleted to ensure the effectiveness of the training
(after eliminating one participant’s data, data from the remaining 39 participants were
analyzed). No significant difference existed in the accuracy of the OTT task between the OTT
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(M = 92.84%, SD = 6.19) and control groups (M = 92.03%, SD = 3.88; t(37) = .47, p = .65).
Therefore, the potential threat to internal validity caused by varying accuracy in the two
groups was excluded. In addition, the high accuracy of both groups (an average of 92%)
indicated that the manipulation of Experiment 1 was effective.
2.2.2 Effect of Overinclusive Thinking Training on the Categorization Task
The results of the t-test for the non-typical exemplars revealed that the performance of
the OTT group (M = 24.45, SD = 5.92) was superior to that of the control group (M = 21.47,
SD = 5.23; t[37] = 1.67, p = .05 [one-tailed], and Cohen’s d = .53). However, no significant
difference in the accuracy of the typical exemplars between the OTT group (M = 59.20, SD =
2.02) and the control group (M = 59.53, SD = .90; t [37] = 0.65, p = .52) was observed. The
results of Experiment 1 showed that after OTT, the typicality level of the non-typical
exemplars increased but that of the typical exemplars did not. The results further indicated
that the OTT improved the participants’ overinclusive thinking.
3. Experiment 2
The results of Experiment 1 revealed the effect of OTT on participants’ overinclusive
thinking. According to previous research, manipulating overinclusive thinking can enhance
creativity (Chrysikou, 2006; Wen et al., 2013) because overinclusive thinking is correlated
with creativity (Eysenck, 2003).Therefore, we explored whether the participants’ creativity
was improved after OTT. In Experiment 2, the training for both groups was the same as that
used in Experiment 1, but the dependent variable was changed from overinclusive thinking to
creativity. Divergent thinking is considered to be a core component of creativity (Guilford,
1967); hence, the divergent thinking task was applied to measure creativity. In addition,
previous studies have demonstrated that variables such as positive emotion (Lyubomirsky,
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King, & Diener, 2005), motivation (Amabile, 1996), and interest (Hirt, Melton, McDonald, &
Harackiewicz, 1996) may influence creativity. These confounding variables were measured
after the training stage for examining whether the manipulation of Experiment 2 influenced
the three variables and, thus, validate whether these confounding variables diminished the
internal validity of Experiment 2. In this experiment, the single-item questionnaire format
proposed by Friedman and Förster (2000, 2001, 2002, 2005) was adopted to measure the
three variables.
3.1 Method
3.1.1 Participants
A total of 42 undergraduates (36 men and 6 women) from the National Defense
University in Taiwan were recruited in Experiment 2.The mean of their ages was 21.03 years
with an SD of 1.22. After eliminating two participants, who had a training accuracy lower
than 70%, the data of the remaining 40 participants were used in statistical analyses.
3.1.2 Materials
3.1.2.1 Creative Thinking Test
This study applied the figural subscale of the Creative Thinking Test (Wu et al., 1998),
which was a divergent thinking test, to measure creative potential. The participants were
asked to draw a picture or an object on the Chinese character “人,” which means “human,”
and name the images they had drawn. Three indicators were assessed in the task: (a) fluency
(the number of responses); (b) originality (unusual responses); and (c) flexibility (the number
of categories of responses).Wu et al. developed the norm of the Creative Thinking Test.
Scores for originality and flexibility could be obtained according to the norm (the score for
fluency is the number of responses). An experienced rater rated the divergent thinking
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abilities of the participants on the basis of the grading standards and the norms. The score for
fluency was calculated according to the total number of responses; and the score for
flexibility was calculated based on the number of categories of responses. Originality was
scored based on the incidence of a certain response in the total normative sample. If 5% or
more of the sample provided the same response, no point was awarded; if 2% to 5% provided
the same response, one point was allocated; and if less than 2% provided the same response,
two points were awarded. The final score for originality was the sum of the points awarded
for each item. The raters began scoring the experimental results after they fully understood
the scoring process. This subscale has a high interrater reliability on fluency, flexibility, and
originality (rs> .94; Wu et al., 1998).
3.1.3 Procedures
The participants were randomly assigned to the OTT group or the control group.
Participants completed the experimental task in a laboratory. The first stage of the experiment
was the training session. After the training, the participants’ mood, their motivation to
participate in the experiment, and their interest in the experiment were measured. The
participants were requested to rate each item on a 7-point Likert scale. For example, “How
happy are you at this moment?” (1 = extremely unhappy, 7 = extremely happy), “How much
effort did you put into this experiment?” (1 = extremely minimal, 7 = extremely substantial),
and “How much were you interested in this experiment?”(1 = extremely disinterested, 7 =
extremely interested). The participants were then required to perform a 10-min Creative
Thinking Test. Following the task, they were asked whether the computerized tasks
influenced their responses on the written test (i.e., Creative Thinking Test). At the end of the
experiment, the purpose of the experiment was explained and a NT$50 coupon was given as a
token of gratitude.
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3.2 Results and Discussion
3.2.1 Accuracy Rates of the Training Task
Data with accuracy below 70% were deleted to ensure the effectiveness of the training
(after eliminating two participants’ data, data from the remaining 40 participants were
analyzed). No significant difference was observed in the accuracy of the OTT task between
the OTT (M = 92.75%, SD = 6.04) and control groups (M = 91.98%, SD = 3.63; t[38] = 0.49,
and p = .63). Therefore, the potential threat to internal validity caused by varying the
accuracy of the two groups was excluded. In addition, the high accuracy of both groups (an
average of 92%) indicated that the manipulation was effective.
3.2.2 Analysis of the Levels of Happiness, Motivation, and Interest
The results regarding the happiness, motivation, and interest of the OTT group were M
= 4.10 and SD = 1.48; M = 5.35 and SD = 1.23, and M = 4.65 and SD = 1.53, respectively,
whereas those of the control group were M = 4.65 and SD = 1.18, M = 5.30 and SD = 1.08,
and M = 4.90 and SD = 1.59, respectively. No significant differences were observed between
the two groups (ts(38)< 1.30, ps> .20). We concluded that the different training or
manipulations used between the OTT and control groups did not have significant differences
in the levels of happiness, motivation, and interest. Therefore, the three variables did not
threaten the internal validity of Experiment 2.
3.2.3 Effects of Overinclusive Thinking Training on the Creative Thinking Test
The measures of three indicators (i.e., fluency, flexibility, and originality) were averaged
ratings calculated by two raters. The intraclass correlations (two-way random model,
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definition of absolute agreement) of three indicators were .99, .97, and .98. Accordingly, the
rating of the Creative Thinking Test was reliable.
The results of the t test indicated that the fluency of the OTT group (M = 17.80, SD =
7.24) was higher than that of the control group (M = 13.55, SD = 4.70; t[32.59] = 2.20, p
= .02[one tail] with Cohen’s d = .70). No significant difference was observed in the flexibility
between the OTT group (M = 10.65, SD = 3.39) and the control group (M = 9.75, SD = 2.59;
t[38] = .94, p = .35). The originality of the OTT group (M = 14.38, SD = 7.95) was higher
than that of the control group (M = 10.20, SD = 4.53; t[30.16] = 2.04, p = .02 with Cohen’s d
= .65).
In addition, when the participants were asked whether the computer task had affected
the Creative Thinking Test, all of them considered the two to be unrelated. The results
indicated that OTT implicitly improved the participants’ creativity without their awareness.
4. Experiment 3
The results of Experiments 1 and 2 revealed that after the participants received OTT,
their overinclusive thinking and divergent thinking were improved, respectively. The purpose
of Experiment 3 was to further investigate the effect of OTT on the improvement in creative
insight. The insight component of creativity was applied as the dependent variable and insight
problems were used to measure insight (Schooler, Ohlsson, & Brooks, 1993). If the effect of
OTT on various creative thinking indicators was significant, the reliability of the training
effect was considered to be robust. In addition, this study involved a discussion of the effect
of OTT comprising various semantic distance designs on creativity enhancement. When
words with long semantic distances were classified into one category, the effect on creativity
enhancement was likely to be substantial because an extensive degree of OTT was achieved.
For example, long-distance semantic OTT may require classifying fruit-related words and
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furniture-related words into a category. Conversely, short-distance semantic OTT requires
classifying words with short semantic distances into a category, such as fruit-related and
vegetable-related words. Therefore, the manipulation of Experiment 3 differed from that of
Experiments 1 and 2 because of the inclusion of an additional short-distance semantic OTT
group.
The difference between the additional condition (i.e., the short-distance semantic OTT)
in Experiment 3 and the OTT group in Experiments 1 and 2 (i.e., the long-distance semantic
OTT) was that in the first and second blocks, the participants were instructed to press the
“left” keyboard when the exemplars from the fruit or vegetable category appeared and the
“right” keyboard when the exemplars from the furniture or housing space category appeared.
In the third and fourth blocks, the participants were instructed to press the “right” keyboard
when the exemplars from the furniture or housing space category appeared and the “left”
keyboard when the exemplars from the fruit or vegetable category appeared. In Experiment 3,
to categorize exemplars from two unrelated categories into one category (e.g., categorizing
the exemplar into the fruit and housing space category by pressing the “left” keyboard), as in
Experiments 1 and 2, was defined as the long-distance semantic OTT task; and the
manipulation of the short-distance semantic OTT task involved categorizing exemplars from
two relatively similar categories into one category (e.g., categorizing the exemplar into the
fruit and vegetable category by pressing the “right” keyboard). In other words, the
long-distance semantic OTT involved categorizing exemplars from two long-distance
semantic categories into one category; however, the short-distance semantic OTT involved
categorizing exemplars from two short-distance semantic categories into one category. In
addition, the task administered to the control group was identical to that performed in
Experiments 1 and 2. In addition to examining the influence of OTT on the improvement of
insight problem solving, the other purpose of Experiment 3 was to investigate the difference
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between the effects of the short- and long-distance semantic OTT.
4.1 Methods
4.1.1 Participants
A total of 59 undergraduates (50 men and 9 women) from the National Defense
University in Taiwan participated in Experiment 3. The mean of their ages was 20.18 years
with an SD of .99. After eliminating three participants, who had a training accuracy lower
than 70%, the data of the remaining 56 participants were used in statistical analyses.
4.1.2 Materials
4.1.2.1 Insight Problems
The three features of insight problems are listed as follows: (a) insight problems can be
solved by anyone; (b) people may reach an impasse and be unable to identify a solution to the
problem; and (c) when a solution is suddenly identified, it is typically accompanied by a
“a-ha” moment (Schooler et al., 1993). To select the insight problems used in the study, we
first collected 20 items from Förster, Friedman, & Liberman (2004), Isaak & Just (1995), and
Metcalfe & Wiebe (1987). The 20 items were presented to 421 university students. Winstep
software was used to conduct a Rasch model difficulty of item analysis (Embretson & Reise,
2000). We selected five problems of medium difficulty, with a mean difficulty (β) of 0.53.
Five insight problems were used in Experiment 3 (five points in total, one point for each
correct answer). An example item is shown as follows:
A prisoner was attempting to escape from a tower. He found in his cell a rope that was
half long enough to permit him to reach the ground safely. He divided the rope in half, tied
the two parts together, and escaped. How could he have done this? (Isaak & Just, 1995).
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4.1.3 Procedures
The participants were randomly assigned to either the long-distance semantic OTT
group, the short–distance semantic OTT group, or the control group. Participants completed
the experimental task in the laboratory. After the training session, the researchers assessed the
extent of the participants’ happiness, motivation to participate, and interest in the
experimental task by using the same items employed in Experiment 2. The participants then
completed a 10-min written test containing insight problems. Following the insight problems,
they were asked to state whether the computerized tasks had influenced their responses to the
written test. At the end of the test, the purpose of the experiment was explained and a NT$50
coupon was given as a token of gratitude.
4.2 Results and Discussion
4.2.1 Accuracy Rates of the Training Tasks
Data with accuracy below 70% were deleted to ensure the effectiveness of the training
(after eliminating three participants’ data, data from the remaining 56 participants were
analyzed). No significant difference existed in the accuracy among the long-distance
semantic OTT group (M = 93.25%, SD = 6.52), the short-distance OTT group (M = 94%, SD
= 3.55), and the control group (M = 91.79%, SD = 4.26), with F (2, 53) = 0 .90 and p = .42.
Therefore, the potential threat to internal validity caused by varying the accuracy of the three
groups was excluded. In addition, the high accuracy of the three groups (an average of 94%)
indicated that the manipulation was effective.
4.2.2 Analysis of the Levels of Happiness, Motivation, and Interest
The results for the happiness, motivation, and interest of the long–distance semantic
OTT group were M = 4.81 and SD = 1.50, M = 5.15 and SD = 1.56, and M = 4.95 and SD =
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1.57, respectively; those of the short-distance semantic OTT group were M = 4.21 and SD =
1.68, M = 5.47 and SD = 1.47, and M = 4.74 and SD = 1.76, respectively; and those of the
control group were M = 3.88 and SD = .99,M = 4.88 and SD = 1.45, and M = 4.12 and SD =
1.41, respectively. The results indicated that no significant difference existed among the three
groups (Fs(2, 53)< 0.85, ps> .40). We concluded that the different manipulations for the three
groups did not cause differences in the extent of happiness, motivation, and interest among
the groups. Therefore, these three confounding variables did not threaten the internal validity
of Experiment 3.
4.2.3 Effects of Overinclusive Thinking Training on Insight Problem Solving
To examine the performance differences in insight problem solving among the three
groups, we conducted a one-way between-groups analysis of variance (ANOVA). We first
conducted a Levene’s test for homogeneity of variance and determined that the results
satisfied the assumption of homogeneity of variance, with F(2, 53) = 3.03 and p = .06, and
were suitable for further ANOVA. The results indicated that significant differences existed in
the performance demonstrated in insight problem solving among the three groups, with F (2,
53) = 3.71, p = .03, and ηp2 = .12. The post hoc comparison revealed that the performance of
the long-distance semantic OTT group (M = 2.50, SD = 1.32) was superior to that of the
control group (M = 1.47, SD = .72); whereas no significant differences existed between the
performance of the short- and long-distance semantic OTT groups (M = 1.95 and SD = 1.27),
or between the short-distance semantic OTT and control groups. In addition, when the
participants were asked whether they believed that the computer tasks had affected their
performance on the written tests, they all considered the two to be unrelated. The results of
Experiment 3 indicated that the long–distance semantic OTT improved the participants’
creativity, but the short-distance semantic OTT did not.
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5. Experiment 4
Experiments 2 to 4 revealed that OTT enhances creativity. However, regarding the
exploration of training effectiveness, the results of Experiments 2 and 3 verified only the
immediate effect of training because the participants were instructed to complete creative
tasks immediately after training. Therefore, the results of these two experiments cannot
validate the delay effect of OTT. To investigate the effect of OTT after a delay of 7 days, we
conducted Experiment 4 by using the same two-group training design and Creative Thinking
Test employed in Experiment 2. The only difference between Experiments 4 and 2 was the
administration time of the creative thinking task. In Experiment 4, the Creative Thinking Test
was administered 7 days after the training to explore the delay effect that OTT has on the
enhancement of creativity.
5.1 Method
5.1.1 Participants
A total of 50 undergraduates (32 men and 18 women) from the National Defense
University in Taiwan participated in Experiment 4. The mean of their ages was 21.26 years
with an SD of 2.10. After eliminating one participant’s data because their training accuracy
was lower than 70%, the data of the remaining 49 participants were used in statistical
analyses.
5.1.2 Procedure
The participants were randomly assigned to the OTT group or the control group. Both
groups received corresponding training, which was identical to that implemented in
Experiment 2. Following a 7-day delay after training, the participants were instructed to
complete the figural subscale of the Creative Thinking Test. Finally, they were asked whether
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the computerized tasks had influenced their responses on the written test. After administering
Experiment 4, the purpose of the experiment was explained and a NT$50 coupon was given
as a token of gratitude.
5.2 Results and Discussion
5.2.1 Accuracy Rates of the Training Task
Data with accuracy below 70% were deleted to ensure the effectiveness of the training
(after eliminating one participant’s data, data from the remaining 49 participants were
analyzed). No significant difference was observed in the accuracy of the OTT task between
the OTT (M = 90.15%, SD = 8.42) and control groups (M = 91.42%, SD = 3.44), with t (47)
= .51 and p = .54. Therefore, the potential threat to internal validity caused by varying the
accuracy of the two groups was excluded. In addition, the high accuracy of both groups (an
average of 91%) indicated that the manipulation was effective.
5.2.2 Effects of Overinclusive Thinking Training on the Creative Thinking Test
The t-test results indicated that the OTT (M = 15.38, SD = 6.62) and control groups (M =
14.16, SD = 5.38) did not exhibit significant differences in the fluency index (t[47] = 0.71, p
= .48). Furthermore, the OTT (M = 9.12, SD = 3.67) and the control groups (M = 10.60, SD =
8.87) did not exhibit significant differences in the flexibility index (t[47] = 0.61, p = .55).
Regarding the originality index, the performance of the OTT group (M = 13.63, SD = 8.26)
was significantly superior to that of the control group (M = 9.88, SD = 5.28; t[47] = 1.90, p
= .03 [one tail], Cohen’s d = .54). In addition, when the participants were asked whether they
believed the computer tasks had affected their performance on the written tests, they all
considered the two to be unrelated. In summary, the results of Experiment 4 indicated that
OTT had a delay effect on originality, but did not affect fluency or flexibility.
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6. Discussion
The creativity training designed in this study was based on the hypothesis that OTT can
enhance people’s overinclusive thinking ability. The results suggested that the training in
which the participants were instructed to categorize seemingly unrelated words into one
category loosened the boundary between conceptual categories, thereby facilitating
overinclusive thinking. The results of Experiment 1 verified that OTT can improve
overinclusive thinking, proving that the training task developed in this study improved
overinclusive thinking and the effectiveness of the training method. The results of
Experiment 2 revealed that OTT enhanced the fluency and originality of the participants’
divergent thinking. However, flexibility was not improved. This may have resulted from
insufficient conceptual association training in which only four word categories were included
in the OTT task of Experiment 2. Although the training improved the participants’ originality
by enabling them to develop unusual ideas through broadened and enhanced scopes of
thinking and concept searching, it failed to improve flexibility. This might be because only a
few category concepts were adopted in the OTT, which further limited the expansion of
thinking categories. The results of Experiment 2 demonstrated that OTT increased the
number of novel knowledge nodes (fluency) and the novelty of ideas. In other words, the
training can improve people’s ability to generate additional ideas and associate categories
among various semantic networks. Through OTT, the scope of knowledge categories can be
expanded, which can further increase the number of semantic associations (Arndt, Greenberg,
& Cook, 2002), thereby improving fluency. Moreover, OTT activates the associations among
remote semantic networks, facilitates the generation of novel ideas, and further improves
originality.
The results from Experiment 3 indicated that long-distance semantic OTT improved the
participants’ insight problem solving, whereas short-distance semantic OTT did not.
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Furthermore, long-distance OTT improved the participants’ creativity; in other words,
long-distance semantic OTT substantially affected creativity improvement. In Experiment 3,
the results revealed that OTT can enhance the performance of insight problemsolving. Insight
problem solving requires a representational change (Knoblich, Ohlsson, Haider, & Rhenius,
1999). After OTT, the ability to make connections among semantic networks was improved.
This might extend the range of knowledge nodes in the brain, facilitate representational
changes, and further overcome obstacles (e.g., fixation) during insight problem solving
(Duncker, 1945). Moreover, the results of Experiment 3 revealed that when the level of OTT
increased, the extent of creativity improvement also increased. In other words, OTT was
effective in creativity improvement when the participants were instructed to classify
seemingly unrelated words from long-distance semantic network categories (e.g., fruit- and
house-related words) into one category during the training. However, when the participants
were required to categorize words from related semantic network categories into the same
category (e.g., fruit- and vegetable-related words), no creativity improvement occurred. These
results provide practical implications for the development of the OTT task: providing a
training task design in which unrelated words can be categorized into one group is necessary.
However, further research is required to investigate another topic regarding the development
of the categorization task: the required length of the semantic distance between two words
from different categories for enhancing creativity.
The results of Experiment 4 revealed that, following a 7-day delay after OTT, the
training still exerted a significant effect on participants’ originality, but not on fluency and
flexibility. This indicates that OTT had both immediate and delayed effects on the originality
of divergent thinking. By contrast, only an immediate effect of OTT on flexibility and
fluency occurred. Possible reasons that delayed training effects on flexibility were not
observed are explained in the previous sections. The remainder of this section provides a
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discussion on the reason no delay effect on fluency occurred.
According to Schooler (2002) and Schooler, Fiore, and Brandimonte (1997), people’s
sequential processing of certain tasks causes processing shifts; namely, after being facilitated
by an earlier cognitive process, the activation of a cognitive process is sustained and then
shifts to subsequent tasks. During transfer-appropriate processing shifts, the residual process
activation facilitates subsequent processing. Therefore, in Experiment 2, when the
participants completed OTT in which they classified seemingly unrelated words into one
category, their relative semantic knowledge nodes were activated. This activation then shifted
to subsequent divergent thinking tasks. In other words, increasing the spread of earlier
knowledge node activation may subsequently improve the performance of fluency, which is
the effect of appropriate processing shifts. Additionally, the results of the meta-analysis on
the effect of creative-improvement training in Ma (2006) indicated that the originality of
divergent thinking had the largest effect size, which was consistent with the data obtained in
this study. In other words, if the divergent thinking test is used in evaluating
creative-improvement training, it can considerably influence originality. Additionally,
another finding of this study is that after OTT, the improvement in originality can be
maintained.
The results of this study indicated that the OTT developed in this study differed from
previous creativity training methods (i.e., rule-based training) because the participants did not
learn specific creative rules. The participants simply performed computer classification tasks
to improve overinclusive thinking and, subsequently, their creativity (changing the remote
association ability of participants directly). Moreover, the participants did not perceive that
their creative capacity was trained when they received OTT. Thus, we developed an
alternative model for creativity training. Explicit creativity training techniques can limit the
search for creative ideas (Zhong et al., 2008), whereas the OTT developed in this study
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involved no such limitations and, thus, provided an advantage when applied.
The creativity-improvement training proposed in this study was developed based
onoverinclusive thinking theory. Although Experiment 1 verified that the participants’
overinclusive thinking increased after their participation in OTT, the results of the
categorization task were used to infer and support the hypothesis of Experiment 1. However,
only indirect evidence was provided to support the hypothesis. In the future, if functional
magnetic resonance imaging (Friston, Ashburner, Kiebel, Nichols, & Penny, 2011) can be
used to examine people’s brain activation patterns during creative thinking following OTT,
relatively direct evidence regarding the effect of OTT can be obtained.
This study examined the effects of OTT on creativity improvement after a 7-day delay,
but the maintenance of effects for longer periods was not examined. Future studies should
explore the delayed effects of training following longer delay periods. In addition, only one
OTT session comprising 480 trials was conducted in this study. Multiple training sessions
conducted over relatively longer periods may increase and reinforce creativity improvement.
Future studies should also investigate the long-term training effects of OTT.
The method of OTT developed in this study produced preliminary effects on creativity
improvement. Thus, this method provides a new training technique for improving creativity.
Particularly for people who have difficulties in learning and using explicit creative skills, the
OTT proposed in this study might be another method for them to improve creative thinking or,
might produce a supplementary effect in traditional explicit creative skill training.
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