High school students' use of meiosis when solving genetics problems

Researchers have pointed out the difficulties that high school students have in understanding meiosis and the infrequency with which they acknowledge the conceptual relationships between meiosis and classical genetics, particularly when solving genetics problems. The research described in this article paints a different picture of students' reasoning with meiosis as they solved complex, computergenerated genetics problems, some of which required them to revise their understanding of meiosis in response to anomalous data. Details are presented of the ways students used their knowledge of meiosis to recognize anomalous data, to generate hypotheses as part of the revision of explanatory models, and to assess these hypotheses. The findings from this research, contrary to most reports in the literature, suggest that students are able to develop rich understanding of meiosis and can utilize that knowledge to solve genetics problems.     

Application of genetics knowledge to the solution of pedigree problems

This paper reports on a study of undergraduate genetics students' conceptual and procedural knowledge and how that knowledge influences students' success in pedigree problem solving. Findings indicate that many students lack the knowledge needed to test hypotheses relating to X-linked modes of inheritance using either patterns of inheritance or genotypes. Case study data illustrate how these knowledge deficiencies acted as an impediment to correct and conclusive solutions of pedigree problems. Specializations: problem solving, laboratory work, conceptual change, science teacher education.     

Meaningful learning,reasoning ability,and students' understanding and problem solving of topics in genetics

The purpose of this study was to explore relationships among school students' (N = 189) meaningful learning orientation, reasoning ability and acquisition of meaningful understandings of genetics topics, and ability to solve genetics problems. This research first obtained measures of students' meaningful learning orientation (meaningful and rote) and reasoning ability (preformal and formal). Students were tested before and after laboratory-based learning cycle genetics instruction using a multiple choice assessment format and an open-ended assessment format (mental model). The assessment instruments were designed to measure students' interrelated understandings of genetics and their ability to solve and interpret problems using Punnett square diagrams. Regression analyses were conducted to examine the predictive influence of meaningful learning orientation, reasoning ability, and the interaction of these variables on students' performance on the different tests. Meaningful learning orientation best predicted students' understanding of genetics interrelationships, whereas reasoning ability best predicted their achievement in solving genetics problems. The interaction of meaningful learning orientation and reasoning ability did not significantly predict students' genetics understanding or problem solving. Meaningful learning orientation best predicted students' performance on all except one of the open-ended test questions. Examination of students' mental model explanations of meiosis, Punnett square diagrams, and relationships between meiosis and the use of Punnett square diagrams revealed unique patterns in students' understandings of these topics. This research provides information for educators on students' acquisition of meaningful understandings of genetics. © 1996 John Wiley & Sons, Inc.     

Teaching for genetics literacy in the post-genomic era

Research in genetics and genomics is advancing at a fast pace, and thus keeping up with the most recent findings and conclusions can be very challenging. At the same time these recent findings and conclusions have made necessary a reconceptualization of genes and heredity, both in science and in science education, beyond the mostly gene-centred view of the twentieth century. The teaching of genetics at schools should have a key role in helping students achieve genetics literacy. However, the literature on research in genetics education reports persistent difficulties and misunderstandings. We first consider the public understanding of and the attitudes towards genetics. Then, we review the most recent literature and present the most typical conceptions found among secondary students in various countries, ages and backgrounds. We argue that particular factors such as intuitive thinking, teachers, textbooks, and the media affect students’ development of erroneous or outdated ideas related to genetics. Finally, we suggest how these problems might be addressed in order for genetics teaching at the secondary level to fulfil the aim of contributing to students’ genetics literacy in the current post-genomic era.     

Cognitive development,genetics problem solving,and genetics instruction: A critical review

Recent studies have analyzed the cognitive demands of solving problems in genetics, focusing primarily on the Piagetian schemas of combinations, proportions, and probability. Based on data from these primarily correlational studies, some authors have argued for the elimination of classical genetics from the high school curriculum. The critical review of the literature presented in this article reaffirms that formal-operational thought is conducive to successful genetics problem solving. The weight of the evidence to date, however, does not support the position that formal operational thought is strictly required for solving typical genetics problems. Arguments are therefore presented in support of the inclusion of genetics and genetics problem solving in high school biology. Implications of this analysis for the selection of appropriate content, problems, and instructional techniques for genetics instruction for nonformal students are presented.     

Definition of historical models of gene function and their relation to students’ understanding of genetics

Models are often used when teaching science. In this paper historical models and students’ ideas about genetics are compared. The historical development of the scientific idea of the gene and its function is described and categorized into five historical models of gene function. Differences and similarities between these historical models are made explicit. Internal and external consistency problems between the models are identified and discussed. From the consistency analysis seven epistemological features are identified. The features vary in such ways between the historical models that it is claimed that learning difficulties might be the consequence if these features are not explicitly addressed when teaching genetics. Students’ understanding of genetics, as described in science education literature, is then examined. The comparison shows extensive parallelism between students’ alternative understanding of genetics and the epistemological features, i.e., the claim is strengthened. It is also argued that, when teaching gene function, the outlined historical models could be useful in a combined nature of science and history of science approach. Our findings also raise the question what to teach in relation to preferred learning outcomes in genetics.     

Expert and novice solutions of genetic pedigree problems

This study compared the problem-solving performance of university genetics professors and genetics students, and therefore fits the expert versus novice paradigm. The subjects solved three genetic pedigree problems. Data were gathered using standard think-aloud protocol procedures. Although the experts did not differ from the novices in terms of the number of correct solutions obtained, there were significant differences favoring the experts in terms of the completeness and conclusiveness of the solutions. The experts identified more critical cues in the pedigrees which were used to generate and test hypotheses, they tested more hypotheses by assigning genotypes to individuals in the pedigrees, and were more rigorous than the novices in the falsification of alternative hypotheses. The experts varied their problem-solving strategy to suit the particular conditions of problems involving rare or common traits. Novices did nor recognize the need to make such modifications to their strategies.     

Problem solving and classical genetics: Successful versus unsuccessful performance

Expert-novice problem-solving research is extended in this study to include classical genetics. Eleven undergraduates (novices) and nine graduate students and instructors (experts) were videotaped as they solved moderately complex genetics problems. Detailed analysis of these “think aloud” protocols resulted in 32 common tendencies that could be used to differentiate between successful and unsuccessful problem solvers. Experts perceive a problem as a task requiring analysis and reasoning and they tend to use a knowledge-development (forward-working) approach. They make frequent checks on the correctness of their work, use accurate and detailed bookkeeping procedures, and have a broader range of heuristics to apply to the problem. It is clear that studying problem solving using the expert/novice design requires that the problems be difficult enough to require more than more recall and yet simple enough to allow novices a chance for solution. Applying elementary probability concepts seemed to be the most difficult aspect of many of the genetics problems, even for the experts.     

An Investigation of Lebanese G7-12 Students’ Misconceptions and Difficulties in Genetics and Their Genetics Literacy

Lebanese educators claim that middle and secondary school students exhibit poor understanding of genetics due to misconceptions and difficulties that hinder progression in conceptual understanding of major genetics concepts and phenomena across different grade levels. They attributed these problems to Lebanon’s ill-structured genetics curriculum which needs a thorough revision in light of curricular reform models that take into account student misconceptions, cognitive abilities, and past experiences. Despite these claims, no empirical tests were done. Consequently, this study aimed to investigate G7-12 Lebanese students’ misconceptions and difficulties in genetics in an attempt to design a curriculum that would enhance student understanding of genetics. Using quantitative and qualitative data collection methods, we obtained an in-depth understanding of the nature of the misconceptions and difficulties encountered by students in grades 7–12, determined the level of students’ genetics literacy, and explored the progression of their level of conceptual understanding of major genetics concepts across grade levels. A questionnaire was administered to 729 students (G7-12) in 6 schools and was followed by semi-structured interviews with 62 students to validate the questionnaire results, gain further understanding of students’ misconceptions, and assess their level of genetics literacy. Findings showed that patterns of inheritance, the deterministic nature of genes, and the nature of genetic information were found to be among the most difficult concepts learned. Students also showed inadequate understanding of many basic genetics concepts which persist across grade levels. Furthermore, results indicated that students across all grade levels exhibited a low level of genetics literacy. Implications for practice and research are discussed.     

Promoting Middle School Students’ Understandings of Molecular Genetics

Genetics is the cornerstone of modern biology and understanding genetics is a critical aspect of scientific literacy. Research has shown, however, that many high school graduates lack fundamental understandings in genetics necessary to make informed decisions or to participate in public debates over emerging technologies in molecular genetics. Currently, much of genetics instruction occurs at the high school level. However, recent policy reports suggest that we may need to begin introducing aspects of core concepts in earlier grades and to successively develop students’ understandings of these concepts in subsequent grades. Given the paucity of research about genetics learning at the middle school level, we know very little about what students in earlier grades are capable of reasoning about in this domain. In this paper, we discuss a research study aimed at fostering deeper understandings of molecular genetics at the middle school level. As part of the research we designed a two-week model-based inquiry unit implemented in two 7th grade classrooms (N = 135). We describe our instructional design and report results based on analysis of pre/post assessments and written artifacts of the unit. Our findings suggest that middle school students can develop: (a) a view of genes as productive instructions for proteins, (b) an understanding of the role of proteins in mediating genetic effects, and (c) can use this knowledge to reason about a novel genetic phenomena. However, there were significant differences in the learning gains in both classrooms and we provide speculative explanations of what may have caused these differences.     

Understanding the Etiology of Complex Traits: Symbiotic Relationships Between Psychology and Genetics

ABSTRACT— The present article offers comments on the infusion of methodologies, approaches, reasoning strategies, and findings from the fields of genetics and genomics into studies of complex human behaviors (hereafter, complex phenotypes). Specifically, I discuss issues of generality and specificity, causality, and replicability as they pertain to molecular genetic studies of human phenotypes. These issues are illustrated with findings from genetic linkage and association studies investigating the etiology of disorders of spoken and written language—an area of inquiry that has been consistently referenced as one of the most successful in terms of its progress in understanding the genetic bases of human behaviors. I complete this discussion with comments on how the stronger presence of genetics and genomics in psychology is changing the conceptualization and investigation of research questions and affecting the next generation of interdisciplinary research.     

Building Capacity in Understanding Foundational Biology Concepts: A K-12 Learning Progression in Genetics Informed by Research on Children’s Thinking and Learning

This article describes the substance, structure, and rationale of a learning progression in genetics spanning kindergarten through twelfth grade (K-12). The learning progression is designed to build a foundation towards understanding protein structure and activity and should be viewed as one possible pathway to understanding concepts of genetics and ultimately protein expression, based on the existing research. The kindergarten through fifth grade segment reflects findings that show children have a rich knowledge base and sophisticated cognitive abilities, and therefore, is designed so that elementary-aged children can learn content in deep and abstract manners, as well as apply scientific explanations appropriate to their knowledge level. The article also details the LP segment facilitating secondary students’ understanding by outlining the overlapping conceptual frames which guide student learning from cell structures and functions to cell splitting (both cell division and gamete formation) to genetics as trait transmission, culminating in genetics as protein expression. The learning progression product avoids the use of technical language, which has been identified as a prominent source of student misconceptions in learning cellular biology, and explicit connections between cellular and macroscopic phenomena are encouraged.     

Expertise and the organization of knowledge: Unexpected differences among genetic counselors,faculty, and students on problem categorization tasks

Chi, Feltovich, and Glaser (1981) observed that experts (physics faculty) organized problems into groups according to the underlying physics law or principle applicable, whereas the groupings of novice physics students focused on objects, literal physics terms, and physical configurations in the problems. Replication of these findings in a number of similar studies has led to the general acceptance of the proposition that the mental schemes used by experts to organize information within a content domain are organized according to the “deep structure” of the domain, whereas the schemes of novices are bound by “surface” dimensions. Categorizations of genetics problems produced by genetics counselor and faculty experts in comparison to student novices obtained in the present study, however, are inconsistent with a deep structure/surface structure dichotomy. As expected, faculty experts focused almost exclusively on conceptual principles, but student sorts focused primarily on problem knowns and unknowns. The expert counselor sortings unexpectedly resembled those of the students in this regard. Counselors also emphasized solution techniques to be used, whereas students emphasized the verbatim wording of the problem statement. These findings are consistent with the hypothesis that as expertise is attained, a person restructures his/her knowledge of the domain into a framework that is based on critical dimensions that facilitate the daily use of that knowledge. Implications for theoreticians, researchers, and teachers are drawn. Whenever possible, future studies of expertise should include noneducator experts; teachers should help students develop the ability to construct and reconstruct the organizational frameworks of their knowledge so as to facilitate the effective use of that knowledge in the face of change.     

Completion problems can reduce the illusions of understanding in a computer-based learning environment on genetics

Inaccurate judgments of task difficulty and invested mental effort may negatively affect how accurate students monitor their own performance. When students are not able to accurately monitor their own performance, they cannot control their learning effectively (e.g., allocate adequate mental effort and study time). Although students' judgments of task difficulty and invested mental effort are closely related to their study behaviors, it is still an open question how the accuracy of these judgments can be improved in learning from problem solving. The present study focused on the impact of three types of instructional support on the accuracy of students' judgments of difficulty and invested mental effort in relation to their performance while learning genetics in a computer-based environment. Sixty-seven university students with different prior knowledge received either incomplete worked-out examples, completion problems, or conventional problems. Results indicated that lower prior knowledge students performed better with completion problems, while higher prior knowledge students performed better with conventional problems. Incomplete worked-out examples resulted in an overestimation of performance, that is, an illusion of understanding, whereas completion and conventional problems showed neither over- nor underestimation. The findings suggest that completion problems can be used to avoid students' misjudgments of their competencies.     

Effect of bead and illustrations models on high school students' achievement in molecular genetics

Our main goal in this study was to explore whether the use of models in molecular genetics instruction in high school can contribute to students' understanding of concepts and processes in genetics. Three comparable groups of 11th and 12th graders participated: The control group (116 students) was taught in the traditional lecture format, while the others received instructions which integrated a bead model (71 students), or an illustration model (71 students). Similar instructions and the same guiding questions accompanied the two models. We used three instruments: a multiple‐choice and an open‐ended written questionnaire, as well as personal interviews. Five of the multiple‐choice questions were also given to students before receiving their genetics instruction (pretest). We found that students who used one of the two types of models improved their knowledge in molecular genetics compared to the control group. However, the open‐ended questions revealed that bead model activity was significantly more effective than illustration activity. On the basis of these findings we conclude that, though it is advisable to use a three‐dimensional model, such as the bead model, engaging students in activities with illustrations can still improve their achievement in comparison to traditional instruction. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 500–529, 2006     

Dynamic and spatial representation of web movements and navigational patterns through the use of navigational paths as data

Solving real-world problems is an effective learning activity that promotes meaningful learning in formal educational settings. Problems can be classified as being either well structured or ill structured. Internet information search approaches have an influential role to play in the successful performance of problem solving. A better understanding of how students differentially model information search strategies and movements in tackling well- and ill-structured problems is essential for creating engaging problem-solving environments for students. Static measures, such as the number of accessed nodes or links, or the number of times particular web browser function buttons are clicked, are limited in their ability to analyze attributes of information search patterns. A more dynamic and spatial representation of web movements and navigational patterns can be realized through the use of navigational paths as data. The two path-specific structural metrics that can be used to assess network-based navigational paths in relation to the structuredness of the problem-solving task are compactness and stratum. These metrics are, respectively, the indicators of the connectedness and linearity of network-based structures defining students’ online navigational visitations during the problem-solving sessions. This study explored the relevance and utility of these two metrics in analyzing the navigational movements of learners in seeking out electronic information to accomplish successful problem solving. The outcome findings of this study show that well- and ill-structured problems demand different cognitive and information seeking navigational approaches. The differing values of the two path metrics in analyzing the search movements organized by students in attending to well- and ill-structured problems were a direct result of the contrasting patterns of navigational path movements. The search patterns associated with well-structured problem solving tended to be more linear and less connected, whereas those related to ill-structured problem solving were more distributed and inter-connected.     

Taking the plunge into the gene pool: Teaching and learning in genetics

Genetics is an area of science that causes problems for children. This paper reviews initial findings from research into children's views of how inheritance works and the role this plays in their overall view of genetics. The implications these results have for the traditional approach to genetics education are outlined. An alternative approach is proposed. Specializations: teacher development, science and technology curriculum development.     

Evaluating Secondary Students’ Scientific Reasoning in Genetics Using a Two‐Tier Diagnostic Instrument

While genetics has remained as one key topic in school science, it continues to be conceptually and linguistically difficult for students with the concomitant debates as to what should be taught in the age of biotechnology. This article documents the development and implementation of a two‐tier multiple‐choice instrument for diagnosing grades 10 and 12 students’ understanding of genetics in terms of reasoning. The pretest and posttest forms of the diagnostic instrument were used alongside other methods in evaluating students’ understanding of genetics in a case‐based qualitative study on teaching and learning with multiple representations in three Western Australian secondary schools. Previous studies have shown that a two‐tier diagnostic instrument is useful in probing students’ understanding or misunderstanding of scientific concepts and ideas. The diagnostic instrument in this study was designed and then progressively refined, improved, and implemented to evaluate student understanding of genetics in three case schools. The final version of the instrument had Cronbach’s alpha reliability of 0.75 and 0.64, respectively, for its pretest and the posttest forms when it was administered to a group of grade 12 students (n = 17). This two‐tier diagnostic instrument complemented other qualitative data collection methods in this research in generating a more holistic picture of student conceptual learning of genetics in terms of scientific reasoning. Implications of the findings of this study using the diagnostic instrument are discussed.     

Deaf and hard of hearing students' performance on arithmetic word problems

There has been limited research into the intersection of language and arithmetic performance of students who are deaf or hard of hearing, although previous research has shown that many of these students are delayed in both language acquisition and arithmetic performance. The researchers examined the performance on arithmetic word problems of deaf and hard of hearing students in the South-East Queensland region of Australia; they also examined these students' problem-solving strategies. It was found that performance on word problems was similar for deaf and hearing students, but that deaf students experienced delays in achieving successful performance on word problems relative to their hearing peers. The results confirm the findings of other studies showing that students who are deaf or hard of hearing experience delayed language acquisition, which affects their capacity to solve arithmetic word problems. The study conclusions stress the need for greater use of direct teaching of analytic and strategic approaches to arithmetic word problems.