Biology Undergraduates' Misconceptions about Genetic Drift

This study explores biology undergraduates' misconceptions about genetic drift. We use qualitative and quantitative methods to describe students' definitions, identify common misconceptions, and examine differences before and after instruction on genetic drift. We identify and describe five overarching categories that include 16 distinct misconceptions about genetic drift. The accuracy of students' conceptions ranges considerably, from responses indicating only superficial, if any, knowledge of any aspect of evolution to responses indicating knowledge of genetic drift but confusion about the nuances of genetic drift. After instruction, a significantly greater number of responses indicate some knowledge of genetic drift (p = 0.005), but 74.6% of responses still contain at least one misconception. We conclude by presenting a framework that organizes how students' conceptions of genetic drift change with instruction. We also articulate three hypotheses regarding undergraduates' conceptions of evolution in general and genetic drift in particular. We propose that: 1) students begin with undeveloped conceptions of evolution that do not recognize different mechanisms of change; 2) students develop more complex, but still inaccurate, conceptual frameworks that reflect experience with vocabulary but still lack deep understanding; and 3) some new misconceptions about genetic drift emerge as students comprehend more about evolution.     

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.     

Understandings and misunderstandings of eighth graders of five chemistry concepts found in textbooks

The research reported in this study was designed to answer three questions: (a) What misconceptions do eighth grade students have concerning the chemistry concepts from their textbooks. (b) How is reasoning ability related to misconceptions concerning chemistry concepts. (c) How effective are textbooks in teaching an understanding of chemistry concepts? Five chemistry concepts were used in the study: chemical change, dissolution, conservation of atoms, periodicity, and phase change. Problems concerning the five concepts were given to 247 eighth-grade students in order to assess the students' degree of understanding of chemistry concepts and to identify specific misconceptions. Two pencil-and-paper Piaget-type tasks were used to assess intellectual level. A comparison of intellectual level and scores on the chemistry concepts showed moderate correlations. However, the small number of formal operational students in the sample makes these results inconclusive. A study of the level of understanding of the five chemistry concepts and the nature of the misconceptions held by students indicate a general failure of textbooks to teach a reasonable understanding of chemistry concepts.     

Development and application of a diagnostic instrument to evaluate grade-11 and -12 students' concepts of covalent bonding and structure following a course of instruction

This article initially outlines a procedure used to develop a written diagnostic instrument to identify grade-11 and -12 students' misconceptions and misunderstandings of the chemistry topic covalent bonding and structure. The content to be taught was carefully defined through a concept map and propositional statements. Following instruction, student understanding of the topic was identified from interviews, student-drawn concept maps, and free-response questions. These data were used to produce 15 two-tier multiple-choice items where the first tier examined content knowledge and the second examined understanding of that knowledge in six conceptual areas, namely, bond polarity, molecular shape, polarity of molecules, lattices, intermolecular forces, and the octet rule. The diagnostic instrument was administered to a total of 243 grade-11 and -12 chemistry students and has a Cronbach alpha reliability of 0.73. Item difficulties ranged from 0.13 to 0.60; discrimination values ranged from 0.32 to 0.65. Each item was analyzed to ascertain student understanding of and identify misconceptions related to the concepts and propositional statements underlying covalent bonding and structure.     

The Dominance Concept Inventory: A Tool for Assessing Undergraduate Student Alternative Conceptions about Dominance in Mendelian and Population Genetics

Despite the impact of genetics on daily life, biology undergraduates understand some key genetics concepts poorly. One concept requiring attention is dominance, which many students understand as a fixed property of an allele or trait and regularly conflate with frequency in a population or selective advantage. We present the Dominance Concept Inventory (DCI), an instrument to gather data on selected alternative conceptions about dominance. During development of the 16-item test, we used expert surveys (n = 12), student interviews (n = 42), and field tests (n = 1763) from introductory and advanced biology undergraduates at public and private, majority- and minority-serving, 2- and 4-yr institutions in the United States. In the final field test across all subject populations (n = 709), item difficulty ranged from 0.08 to 0.84 (0.51 ± 0.049 SEM), while item discrimination ranged from 0.11 to 0.82 (0.50 ± 0.048 SEM). Internal reliability (Cronbach''s alpha) was 0.77, while test–retest reliability values were 0.74 (product moment correlation) and 0.77 (intraclass correlation). The prevalence of alternative conceptions in the field tests shows that introductory and advanced students retain confusion about dominance after instruction. All measures support the DCI as a useful instrument for measuring undergraduate biology student understanding and alternative conceptions about dominance.     

Diagnosing Portuguese Students' Misconceptions about the Mineral Concept

Educational researchers and teachers are well aware that misconceptions—erroneous ideas that differ from the scientifically accepted ones—are very common amongst students. Daily experiences, creative and perceptive thinking and science textbooks give rise to students' misconceptions which lead them to draw erroneous conclusions that become strongly attached to their views and somehow affect subsequent learning. The main scope of this study was to understand what students consider a mineral to be and why. Therefore, the goals were (1) to identify eleventh-grade students' misconceptions about the mineral concept; (2) to understand which variables (gender, parents' education level and attitude towards science) influenced students' conceptions; and (3) to create teaching tools for the prevention of misconceptions. In order to achieve these goals, a diagnostic instrument (DI), constituted of a two-tier diagnostic test and a Science Attitude Questionnaire, was developed to be used with a sample of 89 twelfth-grade students from five schools located in central Portugal. As far as we know, this is the first DI developed for the analysis of misconceptions about the mineral concept. Data analysis allows us to conclude that students had serious difficulties in understanding the mineral concept, having easily formed misconceptions. The variables gender and parents' education level influence certain students' conceptions. This study provides a valuable basis for reflection on teaching and learning strategies, especially on this particular theme.     

A cross-age study of the understanding of five chemistry concepts

A sample of 100 students from junior high school physical science, high school chemistry, and introductory college chemistry were examined for understanding of five chemistry concepts. The concepts addressed were chemical change, dissolution of a solid in water, conservation of atoms, periodicity, and phase change. The amount of experience with the concepts (grade level) and reasoning ability (developmental level) were examined as possible sources of variation in student understanding. Differences in understanding with respect to grade level were found to be significant for the concepts of chemical change, dissolution of a solid, conservation of atoms, and periodicity. However, few of the students in the college chemistry sample exhibited sound understanding of chemical change, periodicity, or phase change. The use of particulate terms (atoms, ions, molecules) increased across the grade levels. Reasoning ability proved to be a significant factor for student understanding of conservation of atoms and periodicity. An examination of the number and types of misconceptions across the grade levels revealed several interesting patterns and suggested sources for the students' alternative conceptions.     

A cross-age study of student understanding of the concept of diffusion

This study examined 7th-grade life science students, 10th-grade biology students, and college zoology students for understanding of the concept of diffusion. Responses from 100 students from each grade level were randomly selected for data analysis. Each student responded to a test packet consisting of a biographical questionnaire, two Piagetian-like developmental tasks, and a Concept Evaluation Statement (CES). The CESs were used to measure the students' understandings of the concept of diffusion. None of the 300 students across the three grade levels exhibited complete understanding of the diffusion concept. There was no appreciable difference among the grade levels in sound or partial understanding, misconceptions, or “no understanding.” An analysis of the misconceptions exhibited by the college sample showed that many of the misconceptions could be traced to a misapplication of scientific terminology.     

Six Classroom Exercises to Teach Natural Selection to Undergraduate Biology Students

Students in introductory biology courses frequently have misconceptions regarding natural selection. In this paper, we describe six activities that biology instructors can use to teach undergraduate students in introductory biology courses how natural selection causes evolution. These activities begin with a lesson introducing students to natural selection and also include discussions on sexual selection, molecular evolution, evolution of complex traits, and the evolution of behavior. The set of six topics gives students the opportunity to see how natural selection operates in a variety of contexts. Pre- and postinstruction testing showed students’ understanding of natural selection increased substantially after completing this series of learning activities. Testing throughout this unit showed steadily increasing student understanding, and surveys indicated students enjoyed the activities.     

Undergraduates Achieve Learning Gains in Plant Genetics through Peer Teaching of Secondary Students

This study tests the hypothesis that undergraduates who peer teach genetics will have greater understanding of genetic and molecular biology concepts as a result of their teaching experiences. Undergraduates enrolled in a non–majors biology course participated in a service-learning program in which they led middle school (MS) or high school (HS) students through a case study curriculum to discover the cause of a green tomato variant. The curriculum explored plant reproduction and genetic principles, highlighting variation in heirloom tomato fruits to reinforce the concept of the genetic basis of phenotypic variation. HS students were taught additional activities related to mole­cular biology techniques not included in the MS curriculum. We measured undergraduates’ learning outcomes using pre/postteaching content assessments and the course final exam. Undergraduates showed significant gains in understanding of topics related to the curriculum they taught, compared with other course content, on both types of assessments. Undergraduates who taught HS students scored higher on questions specific to the HS curriculum compared with undergraduates who taught MS students, despite identical lecture content, on both types of assessments. These results indicate the positive effect of service-learning peer-teaching experiences on undergraduates’ content knowledge, even for non–science major students.     

A Deliberate Practice Approach to Teaching Phylogenetic Analysis

One goal of postsecondary education is to assist students in developing expert-level understanding. Previous attempts to encourage expert-level understanding of phylogenetic analysis in college science classrooms have largely focused on isolated, or “one-shot,” in-class activities. Using a deliberate practice instructional approach, we designed a set of five assignments for a 300-level plant systematics course that incrementally introduces the concepts and skills used in phylogenetic analysis. In our assignments, students learned the process of constructing phylogenetic trees through a series of increasingly difficult tasks; thus, skill development served as a framework for building content knowledge. We present results from 5 yr of final exam scores, pre- and postconcept assessments, and student surveys to assess the impact of our new pedagogical materials on student performance related to constructing and interpreting phylogenetic trees. Students improved in their ability to interpret relationships within trees and improved in several aspects related to between-tree comparisons and tree construction skills. Student feedback indicated that most students believed our approach prepared them to engage in tree construction and gave them confidence in their abilities. Overall, our data confirm that instructional approaches implementing deliberate practice address student misconceptions, improve student experiences, and foster deeper understanding of difficult scientific concepts.     

Teaching and learning the concept of chemical bonding

Chemical bonding is one of the key and basic concepts in chemistry. The learning of many of the concepts taught in chemistry, in both secondary schools as well as in the colleges, is dependent upon understanding fundamental ideas related to chemical bonding. Nevertheless, the concept is perceived by teachers, as well as by learners, as difficult, with teaching commonly leading to students developing misconceptions. Many of these misconceptions result from over‐simplified models used in text books, by the use of traditional pedagogy that presents a rather limited and sometimes incorrect picture of the issues related to chemical bonding and by assessments of students' achievement that influence the way the topic is taught. In addition, there are discrepancies between scientists regarding key definitions in the topic and the most appropriate models to teach it. In particular, teaching models that are intended to have transitional epistemological value in introducing abstract ideas are often instead understood by students as accounts of ontological reality. In this review paper we provide science educators, curricula developers and pre‐service and in‐service professional development providers an up‐to‐date picture regarding research and developments in teaching about chemical bonding. We review the external and internal variables that might lead to misconceptions and the problematic issue of using limited teaching/learning models. Finally, we review the approaches to teaching the concept that might overcome some of these misconceptions.     

The EvoDevoCI: A Concept Inventory for Gauging Students’ Understanding of Evolutionary Developmental Biology

The American Association for the Advancement of Science 2011 report Vision and Change in Undergraduate Biology Education encourages the teaching of developmental biology as an important part of teaching evolution. Recently, however, we found that biology majors often lack the developmental knowledge needed to understand evolutionary developmental biology, or “evo-devo.” To assist in efforts to improve evo-devo instruction among undergraduate biology majors, we designed a concept inventory (CI) for evolutionary developmental biology, the EvoDevoCI. The CI measures student understanding of six core evo-devo concepts using four scenarios and 11 multiple-choice items, all inspired by authentic scientific examples. Distracters were designed to represent the common conceptual difficulties students have with each evo-devo concept. The tool was validated by experts and administered at four institutions to 1191 students during preliminary (n = 652) and final (n = 539) field trials. We used student responses to evaluate the readability, difficulty, discriminability, validity, and reliability of the EvoDevoCI, which included items ranging in difficulty from 0.22–0.55 and in discriminability from 0.19–0.38. Such measures suggest the EvoDevoCI is an effective tool for assessing student understanding of evo-devo concepts and the prevalence of associated common conceptual difficulties among both novice and advanced undergraduate biology majors.     

Conceptual change strategies and cooperative group work in chemistry

This study conducted at a suburban community college tested a method of conceptual change in which treatment students worked in small cooperative groups on tasks aimed at eliciting their misconceptions so that they could then be discussed in contrast to the scientific conceptions that had been taught in direct instruction. Categorizations of student understanding of the target concepts of the laws of conservation of matter and energy and aspects of the particulate nature of gases, liquids, and solids were ascertained by pre- and posttesting. Audiotapes of student verbal interaction in the small groups provided quantitative and qualitative data concerning student engagement in behaviors suggestive of the conditions posited to be part of the conceptual change process (Posner, Strike, Hewson & Gertzog, 1982). Chi-square analysis of posttests indicated that students in treatment groups had significantly lower (p < 0.05) proportion of misconceptions than control students on four of the five target concepts. Students who exhibited no change in concept state had a higher frequency of verbal behaviors suggestive of “impeding” conceptual change when compared to students who did change. Three factors emerged from qualitative analysis of group interaction that appeared to influence learning: (a) many students had flawed understanding of concepts that supported the target concepts; (b) student views towards learning science affected their engagement in assigned tasks, (c) “good” and “poor” group leaders had a strong influence on group success.     

How do students misunderstand number representations?

We used both student interviews and diagnostic testing to reveal students’ misconceptions about number representations in computing systems. This article reveals that students who have passed an undergraduate level computer organization course still possess surprising misconceptions about positional notations, two's complement representation, and overflow. Contrary to common opinion, these misconceptions are widespread and reveal the need for instruction that specifically targets these misconceptions. In addition, these misconceptions will serve as the basis for the creation of a standard assessment tool called the digital logic concept inventory. This concept inventory will provide a rigorous and quantitative metric to assess the effectiveness of new teaching methods.     

Development and Effectiveness of an Educational Card Game as Supplementary Material in Understanding Selected Topics in Biology

The complex concepts and vocabulary of biology classes discourage many students. In this study, a pretest–posttest model was used to test the effectiveness of an educational card game in reinforcing biological concepts in comparison with traditional teaching methods. The subjects of this study were two biology classes at Bulacan State University–Sarmiento Campus. Both classes received conventional instruction; however, the experimental group''s instruction was supplemented with the card game, while the control group''s instruction was reinforced with traditional exercises and assignments. The score increases from pretest to posttest showed that both methods effectively reinforced biological concepts, but a t test showed that the card game is more effective than traditional teaching methods. Additionally, students from the experimental group evaluated the card game using five criteria: goals, design, organization, playability, and usefulness. The students rated the material very satisfactory.     

Grade-12 students' misconceptions relating to fundamental characteristics of atoms and molecules

An understanding of the concepts of atom and molecule is fundamental to the learning of chemistry. Any misconceptions and alternative conceptions that students harbor about these concepts will impede further learning. This article identifies misconceptions related to the fundamental characteristics of atoms and molecules which Grade-12 students hold. Data were obtained by administration of semistructured interviews to a stratified, random sample of 30 students of differing abilities and backgrounds in science. Fifty-two misconceptions were observed and are reported. These are grouped into 11 categories. Six relate to the structure, composition, size, shape, weight, bonding, and energy of molecules; five relate to the structure, shape, size, weight, and animistic perceptions of atoms. Some of the misconceptions identified parallel the historical development of scientific concepts.     

The influence of wait‐time on classroom learning

This study describes a lesson in which students engaged in inquiry in evolutionary biology in order to develop a better understanding of the concepts and reasoning skills necessary to support knowledge claims about changes in the genetic structure of populations, also known as microevolution. This paper describes how a software simulation called EVOLVE can be used to foster discussions about the conceptual knowledge used by advanced secondary or introductory college students when investigating the effects of natural selection on hypothetical populations over time. An experienced professor's use and rationale of a problem-based lesson using the simulation is examined. Examples of student misconceptions and naïve (incomplete) conceptions are described and an analysis of the procedural knowledge for experimenting with the computer model is provided. The results of this case study provide a model of how EVOLVE can be used to engage students in a complex problem-solving experience that encourages student meta-cognitive reflection about their understanding of evolution at the population level. Implications for teaching are provided and ways to improve student learning and problem solving in population genetics are suggested.     

Prospective chemistry teachers' conceptions of the conservation of matter and related concepts

This study investigated the quality and extent of understanding of certain well-known theoretical concepts which prospective teachers of chemistry in Yemen possess. In addition to the concepts of the conservation of atoms and mass, and the mole, the concepts of atomic mass and balancing chemical equations were chosen for this study. An instrument was built first, then administered to 173 junior and senior prospective chemistry teachers. The results showed that the prospective teachers' understandings of most of the concepts ranged from a partial understanding with specific misconception to no understanding. Only on balancing chemical equations did the prospective teachers show good understanding. The results showed that most prospective teachers depended on mere memorization of the concepts without meaningful understanding. It also found that the prospective teachers' knowledge about the concepts was fragmented and not correlated. The study attributed the prospective teachers' misconceptions to defective instruction. Finally, the study concluded that more effective teaching methods are needed to ensure a sound understanding of these concepts. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 181–197, 1997.     

Connected Chemistry—Incorporating Interactive Simulations into the Chemistry Classroom

The aim of this paper is to describe a novel modeling and simulation package, connected chemistry, and assess its impact on students' understanding of chemistry. Connected chemistry was implemented inside the NetLogo modeling environment. Its design goal is to present a variety of chemistry concepts from the perspective of emergent phenomena—that is, how macro-level patterns in chemistry result from the interactions of many molecules on a submicro-level. The connected chemistry modeling environment provides students with the opportunity to observe and explore these interactions in a simulated environment that enables them to develop a deeper understanding of chemistry concepts and processes in both the classroom and laboratory. Here, we present the conceptual foundations of instruction using connected chemistry and the results of a small study that explored its potential benefits. A three-part, 90-min interview was administered to six undergraduate science majors regarding the concept of chemical equilibrium. Several commonly reported misconceptions about chemical equilibrium arose during the interview. Prior to their interaction with connected chemistry, students relied on memorized facts to explain chemical equilibrium and rigid procedures to solve chemical equilibrium problems. Using connected chemistry students employed problem-solving techniques characterized by stronger attempts at conceptual understanding and logical reasoning.