JOURNAL OF RESEARCH IN SCIENCE TEACHING
VOL. 45, NO. 3, PP. 273–292 (2008)
Using Computer Animation and Illustration Activities to Improve High School
Students’ Achievement in Molecular Genetics
Gili Marbach-Ad,1,2 Yosi Rotbain,1 Ruth Stavy1
1
2
School of Education/Humanities, Tel Aviv University, Ramat-Aviv, Tel Aviv, Israel
College 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.
ß 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: gilim@umd.edu
DOI 10.1002/tea.20222
Published online 5 December 2007 in Wiley InterScience (www.interscience.wiley.com).
ß 2007 Wiley Periodicals, Inc.
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MARBACH-AD, ROTBAIN, AND STAVY
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
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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
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MARBACH-AD, ROTBAIN, AND STAVY
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
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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
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MARBACH-AD, ROTBAIN, AND STAVY
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.
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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.
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MARBACH-AD, ROTBAIN, AND STAVY
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.
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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 of
Questionnaire
Computer
(N ¼ 61)
Illustration
(N ¼ 71)
Control
(N ¼ 116)
F
Paired Comparisons
b
Multiple-choice
questionnaire
74 (19)
70 (21)
61 (21)
11.32
Open-ended
questionnaire
68 (16)
58 (19)
46 (22)
32.23b
Computer/controlb
Illustration/controlb
Computer/illustration
Computer/controlb
Illustration/controlb
Computer/illustrationa
a
p < 0.01; bp < 0.001.
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MARBACH-AD, ROTBAIN, AND STAVY
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
Subtopic
Computer
(N ¼ 61)
Illustration
(N ¼ 71)
Control
(N ¼ 116)
F
Paired Comparisons
a
DNA and RNA structure
81 (24)
77 (29)
69 (34)
4.23
Transcription and translation
63 (29)
54 (32)
43 (31)
8.83c
The relationships between
DNA and protein
77 (21)
78 (24)
69 (25)
5.57b
a
p < 0.05; bp < 0.01; cp < 0.001.
Journal of Research in Science Teaching. DOI 10.1002/tea
Computer/controlb
Illustration/controla
Computer/illustration
Computer/controlc
Illustration/controla
Computer/illustration
Computer/controla
Illustration/controlb
Computer/illustration
COMPUTER ILLUSTRATION AND ANIMATION
283
Table 3
Average scores and standard deviations (in parentheses) for groups of questions related to the same
subtopic in the open-ended questionnaire
Subtopic
Computer
(N ¼ 61)
Illustration
(N ¼ 71)
Control
(N ¼ 116)
F
Paired Comparisons
b
DNA and RNA structure
82 (13)
76 (20)
60 (25)
30.80
Transcription and translation
69 (24)
56 (30)
40 (29)
25.48c
The relationships between
DNA and protein
48 (24)
37 (25)
34 (26)
8.15c
Computer/controlb
Illustration/controlb
Computer/illustration
Computer/controlb
Illustration/controlb
Computer/illustrationa
Computer/controlc
Illustration/control
Computer/illustrationb
a
p < 0.01; bp < 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%;
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MARBACH-AD, ROTBAIN, AND STAVY
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 multiplechoice 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’’).
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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.
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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
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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
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MARBACH-AD, ROTBAIN, AND STAVY
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 thoughtprovoking.
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).
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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):
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MARBACH-AD, ROTBAIN, AND STAVY
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:
Average Scores
Subtopic
DNA and RNA
structure
Transcription and
translation
The relationships
between DNA
and protein
Questions
1. What is DNA?
2. Write a sentence that
includes the concepts
nucleotide and nitrogen
base.
3. Complete the following
sentences:
(a) The four nucleotides
of DNA have in
common. . ..
(b) The differences between
the four nucleotides of
DNA are due to. . ..
4. Is information about the
sequence of one strands
of DNA sufficient to
determine the sequence of
the other strand?
5. How does DNA replication
occur in the cell?
8. Can the translation process
occur without the
transcription process?
Explain your answer.
9. Can protein synthesis
occur without the presence
of t-RNA? Explain your
answer.
6. Write a sentence that
includes the concepts DNA
and protein.
7. What is the genetic code?
10. You were asked to design a
gene that codes for insulin.
Which information do you
need in order to do it?
Explain your answer.
Computer
(N ¼ 61)
Illustration
(N ¼ 71)
Control
(N ¼ 116)
F
77 (20)
66 (26)
65 (25)
5.03a
94 (18)
81 (32)
60 (44)
20.49b
79 (30)
79 (32)
46 (41)
27.89b
79 (25)
78 (24)
68 (29)
5.28a
79 (31)
58 (44)
40 (44)
19.87b
72 (33)
67 (32)
44 (33)
20.31b
57 (33)
43 (35)
37 (33)
25.16b
63 (35)
49 (39)
41 (41)
7.58a
44 (29)
38 (40)
31 (23)
32 (37)
32 (32)
29 (36)
4.35
1.32
a
p < 0.05; bp < 0.001.
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