Teaching statistics in biology: using inquiry-based learning to strengthen understanding of statistical analysis in biology laboratory courses

There is an increasing need for students in the biological sciences to build a strong foundation in quantitative approaches to data analyses. Although most science, engineering, and math field majors are required to take at least one statistics course, statistical analysis is poorly integrated into undergraduate biology course work, particularly at the lower-division level. Elements of statistics were incorporated into an introductory biology course, including a review of statistics concepts and opportunity for students to perform statistical analysis in a biological context. Learning gains were measured with an 11-item statistics learning survey instrument developed for the course. Students showed a statistically significant 25% (p < 0.005) increase in statistics knowledge after completing introductory biology. Students improved their scores on the survey after completing introductory biology, even if they had previously completed an introductory statistics course (9%, improvement p < 0.005). Students retested 1 yr after completing introductory biology showed no loss of their statistics knowledge as measured by this instrument, suggesting that the use of statistics in biology course work may aid long-term retention of statistics knowledge. No statistically significant differences in learning were detected between male and female students in the study.     

An experimental test of an extended discretion laboratory approach for university general biology

This was an experiment to test the extended discretion laboratory approach (ED) versus a guided-inquiry (GI) approach for teaching biology in a university setting. It had previously been found productive in a high-school setting. The approach provides considerably less specific procedure for the students to follow than did a guided-inquiry approach and required relatively high independence. Four hundred sixty-nine students taking university introductory biology were randomly assigned to using either the ED learning approach or one characterized as guided inquiry for one semester. Three measures were taken to verify that instructional treatments followed the two approaches. All indicated qualitative and quantitative differences between ED and GI approaches in the direction predicted by the operational definitions. The criterion variables were (1) student scores on a multiple-choice laboratory exam, (2) student scores on laboratory reports, and (3) student scores on six laboratory quizzes given during the semester. The only criterion variable which showed significant differences between groups (laboratory-report scores) also showed significant group-by-instructor interaction. The hypothesis of no difference therefore stood unrejected for all criterion variables. Since the ED approach appears to produce equivalent learning gains in understanding of biology laboratory concepts compared to a guided-inquiry approach, this approach should still be considered for laboratory teaching, because it purports to train for discretionary use of resources during instruction in addition to the conventional development of laboratory concepts.     

A comparison of student reactions to biology instruction by interactive videodisc or conventional laboratory

This study was designed to learn if students perceived an interactive computer/videodisc learning system to represent a viable alternative to (or extension of) the conventional laboratory for learning biology skills and concepts normally taught under classroom laboratory conditions. Data were collected by questionnaire for introductory biology classes at a large midwestern university where students were randomly assigned to two interactive videodisc/computer lessons titled Respiration and Climate and Life or traditional laboratory investigation with the same titles and concepts. The interactive videodisc system consisted of a TRS-80 Model III microcomputer interfaced to a Pioneer laser-disc player and a color TV monitor. Students indicated an overall level satisfaction with this strategy very similar to that of conventional laboratory instruction. Students frequently remarked that videodisc instruction gave them more experimental and procedural options and more efficient use of instructional time than did the conventional laboratory mode. These two results are consistent with past CAI research. Students also had a strong perception that the images on the videodisc “were not real” and this factor was perceived as having both advantages and disadvantages. Students found the two approaches to be equivalent to conventional laboratory instruction in the areas of general interest, understanding of basic principles, help on examinations, and attitude toward science. The student-opinion data in this study do not suggest that interactive videodisc technology serve as a substitute to the “wet” laboratory experience, but that this medium may enrich the spectrum of educational experiences usually not possible in typical classroom settings.     

Utility value interventions in a college biology lab: The impact on motivation

Science writing, such as lab reports, allows students to form a meaningful understanding of scientific concepts. However, students often view scientific writing as unimportant and utilize surface level approaches when completing writing assignments. The current study implemented three experimental interventions (directly-communicated, self-generated, and hybrid) aligned with prior literature and designed to improve the utility value of lab reports in college settings. Participants (n = 1,002) were recruited from 43 lab sections of an introductory biology course at a large southeastern university. Measures of subjective task value (utility value, attainment value, cost, and intrinsic value) were collected pre-, mid-, and post-intervention. The self-generated and hybrid groups exhibited higher self-reported utility value by posttest compared to the control group. Requiring students to generate their own utility value toward a task, followed by a written reflection, increases students' maintained and situational interest for biology laboratory reports.     

Cooperative learning in industrial-sized biology classes

This study examined the impact of cooperative learning activities on student achievement and attitudes in large-enrollment (>250) introductory biology classes. We found that students taught using a cooperative learning approach showed greater improvement in their knowledge of course material compared with students taught using a traditional lecture format. In addition, students viewed cooperative learning activities highly favorably. These findings suggest that encouraging students to work in small groups and improving feedback between the instructor and the students can help to improve student outcomes even in very large classes. These results should be viewed cautiously, however, until this experiment can be replicated with additional faculty. Strategies for potentially improving the impact of cooperative learning on student achievement in large courses are discussed.     

Using reasoning ability as the basis for assigning laboratory partners in nonmajors biology

Students in a large one-semester nonmajors college biology course were classified into one of three groups (intuitive—I, transitional—T, reflective—R) based upon a pretest of scientific reasoning ability. Laboratory teams of two students each then were formed, such that all possible combinations of reasoning abilities were represented (i.e., I-I, I-T, I-R, T-T, T-R, R-R). Students worked with their assigned partners during each of the course's 14 laboratory sessions. Gains in reasoning ability, laboratory achievement, and course achievement, as well as changes in students' opinions of their motivation, enjoyment of the laboratory, and their own and their partner's reasoning abilities were assessed at the end of the semester. Significant pre- to posttest gains in reasoning ability by the intuitive and transitional students were found, but these gains were not significantly related to the laboratory partner's reasoning ability. Also, course achievement was not significantly related to the laboratory partner's reasoning ability. Students were perceptive of others' reasoning ability; the more able reasoners were generally viewed as being more motivated, having better ideas, and being better at doing science. Additional results also indicated that course enjoyment and motivation was significantly decreased for the transitional students when they were paired with intuitive students. Apparently, for students in transition (i.e., not at an equilibrium state with regard to reasoning level), it is frustrating to work with a less able reasoner. However, some evidence was found to suggest that reflective students may benefit from working with a less able partner.     

Understanding cellular respiration: An analysis of conceptual change in college biology

This study explored and documented the frequencies of conceptual difficulties confronted by college students seeking to understand the basic processes of cellular respiration. Using concept maps, clinical interviews and an open-ended instrument, viewpoints were elicited from 100 (novice) introductory biology students before and after relevant instruction in cellular respiration and from 100 (experienced) students enrolled in advanced biology courses. Chi-square analyses revealed significant differences among groups in the frequencies of scientifically acceptable and alternative conceptions. The findings suggest that novices harbor a wide range of conceptual difficulties that constrain their understanding of cellular respiration. Furthermore, many of these difficulties persist after instruction and new ones arise. Often these conceptual problems remain intact among experienced students despite well-planned, repeated instruction at advanced levels.     

Using the web to encourage student-generated questions in large-format introductory biology classes

Students rarely ask questions related to course content in large-format introductory classes. The use of a Web-based forum devoted to student-generated questions was explored in a second-semester introductory biology course. Approximately 80% of the enrolled students asked at least one question about course content during each of three semesters during which this approach was implemented. About 95% of the students who posted questions reported reading the instructor's response to their questions. Although doing so did not contribute to their grade in the course, approximately 75% of the students reported reading questions posted by other students in the class. Approximately 60% of the students reported that the Web-based question-asking activity contributed to their learning of biology.     

Culturally relevant inquiry-based laboratory module implementations in upper-division genetics and cell biology teaching laboratories

Today, more minority students are entering undergraduate programs than ever before, but they earn only 6% of all science or engineering PhDs awarded in the United States. Many studies suggest that hands-on research activities enhance students' interest in pursuing a research career. In this paper, we present a model for the implementation of laboratory research in the undergraduate teaching laboratory using a culturally relevant approach to engage students. Laboratory modules were implemented in upper-division genetics and cell biology courses using cassava as the central theme. Students were asked to bring cassava samples from their respective towns, which allowed them to compare their field-collected samples against known lineages from agricultural stations at the end of the implementation. Assessment of content and learning perceptions revealed that our novel approach allowed students to learn while engaged in characterizing Puerto Rican cassava. In two semesters, based on the percentage of students who answered correctly in the premodule assessment for content knowledge, there was an overall improvement of 66% and 55% at the end in the genetics course and 24% and 15% in the cell biology course. Our proposed pedagogical model enhances students' professional competitiveness by providing students with valuable research skills as they work on a problem to which they can relate.     

From Genes to Proteins to Behavior: A Laboratory Project That Enhances Student Understanding in Cell and Molecular Biology

In the laboratory, students can actively explore concepts and experience the nature of scientific research. We have devised a 5-wk laboratory project in our introductory college biology course whose aim was to improve understanding in five major concepts that are central to basic cellular, molecular biology, and genetics while teaching molecular biology techniques. The project was focused on the production of adenine in Saccharomyces cerevisiae and investigated the nature of mutant red colonies of this yeast. Students created red mutants from a wild-type strain, amplified the two genes capable of giving rise to the red phenotype, and then analyzed the nucleotide sequences. A quiz assessing student understanding in the five areas was given at the start and the end of the course. Analysis of the quiz showed significant improvement in each of the areas. These areas were taught in the laboratory and the classroom; therefore, students were surveyed to determine whether the laboratory played a role in their improved understanding of the five areas. Student survey data demonstrated that the laboratory did have an important role in their learning of the concepts. This project simulated steps in a research project and could be adapted for an advanced course in genetics.     

A diagnostic assessment for introductory molecular and cell biology

We have developed and validated a tool for assessing understanding of a selection of fundamental concepts and basic knowledge in undergraduate introductory molecular and cell biology, focusing on areas in which students often have misconceptions. This multiple-choice Introductory Molecular and Cell Biology Assessment (IMCA) instrument is designed for use as a pre- and posttest to measure student learning gains. To develop the assessment, we first worked with faculty to create a set of learning goals that targeted important concepts in the field and seemed likely to be emphasized by most instructors teaching these subjects. We interviewed students using open-ended questions to identify commonly held misconceptions, formulated multiple-choice questions that included these ideas as distracters, and reinterviewed students to establish validity of the instrument. The assessment was then evaluated by 25 biology experts and modified based on their suggestions. The complete revised assessment was administered to more than 1300 students at three institutions. Analysis of statistical parameters including item difficulty, item discrimination, and reliability provides evidence that the IMCA is a valid and reliable instrument with several potential uses in gauging student learning of key concepts in molecular and cell biology.     

细胞生物学实验课程的教改探索

作为生命科学以及生物技术专业的必修课,细胞生物学是一门以实验为基础的学科。细胞生物实验教学既是培养学生观察能力和实验能力的重要环节,也是培养学生科学素质的有效途径。从拓展教学手段、丰富教学内容以及完善考核方式三个方面进行了教改探讨,以期提高学生的创新意识和学习兴趣,从而实现培养新世纪复合型人才的目标。     

Implementation of the Peer-Led Team-Learning Instructional Model as a Stopgap Measure Improves Student Achievement for Students Opting Out of Laboratory

In entry-level university courses in science, technology, engineering, and mathematics fields, students participating in associated laboratory sessions generally do better than those who have no related lab classes. This is a problem when, for various reasons, not enough lab sections can be offered for students and/or when students opt out of optional available lab courses. Faced with such a situation, this study evaluated the efficacy of the peer-led team-learning (PLTL) instructional model as a potential method for narrowing the achievement gap among undergraduate students electing not to enroll in an optional laboratory component of an introductory biology course. In peer-led workshops, small groups of students participated in solving problems and other activities that encouraged active learning. Students led by peer leaders attained significantly higher exam and final course grades in introductory biology than comparable students not participating in PLTL. Among the introductory biology students who opted not to enroll in the optional lab course, those who participated in PLTL averaged more than a letter grade higher than those who did not. This difference was statistically significant, and the PLTL workshops almost entirely closed the achievement gap in lecture exam and final grades for students who did not take the lab.     

From organelle to protein gel: a 6-wk laboratory project on flagellar proteins

Research suggests that undergraduate students learn more from lab experiences that involve longer-term projects. We have developed a one-semester laboratory sequence aimed at sophomore-level undergraduates. In designing this curriculum, we focused on several educational objectives: 1) giving students a feel for the scientific research process, 2) introducing them to commonly used lab techniques, and 3) building skills in both data analysis and scientific writing. Over the course of the semester, students carry out two project-based lab experiences and write two substantial lab reports modeled on primary literature. Student assessment data indicate that this lab curriculum achieved these objectives. This article describes the first of these projects, which uses the biflagellate alga Chlamydomonas reinhardtii to introduce students to the study of flagellar motility, protein synthesis, microtubule polymerization, organelle assembly, and protein isolation and characterization.     

Assessing practical laboratory skills in undergraduate molecular biology courses

This study explored a new strategy of assessing laboratory skills in a molecular biology course to improve: student effort in preparation for and participation in laboratory work; valid evaluation of learning outcomes; and students’ employment prospects through provision of evidence of their skills. Previously, assessment was based on written laboratory reports and examinations, not on the demonstration of practical skills per se. This action research project involved altering the assessment design so that a greater proportion of the marks was allocated to active participation and learning in the laboratory, partially replacing a single examination with direct observation of student participation and learning over a prolonged period of weekly laboratory sessions. We ascertained staff and students’ perceptions of the new assessment processes by means of a Likert scale questionnaire, student focus group and individual staff interviews. Overall, students and staff evaluated the new assessment structure positively, citing fairness, authenticity and reward for effort. Results also revealed the need for specific training of staff in this form of assessment and indicated staff–student ratios made assessment burdensome. Four out of five students reported that an increased awareness of the importance of practical laboratory skills stimulated them to greater efforts to achieve.     

Factors influencing student perceptions of high-school science laboratory environments

Science laboratory learning has been lauded for decades for its role in fostering positive student attitudes about science and developing students’ interest in science and ability to use equipment. An expanding body of research has demonstrated the significant influence of laboratory environment on student learning. Further research has demonstrated differences in student perceptions based on giftedness. To explore the relationship between giftedness and students’ perceptions of their learning environment, we examined students’ perceptions of their laboratory learning environment in biology courses, including courses designated for high-achieving versus regular-achieving students. In addition, to explore the relationship between students’ perceptions and the extent of their experience with laboratory learning in a particular discipline, we examined students’ perceptions of their laboratory learning environment in first-year biology courses versus elective biology courses that require first-year biology as a prerequisite. We found that students in high-achieving courses had a more favourable perception of all aspects of their learning environment when compared with students in regular courses. In addition, student perceptions of their laboratory appeared to be influenced by the extent of their experience in learning science. Perceptions were consistent amongst regular- and high-achieving students regardless of grade level. In addition, perceptions of students in first year and beyond were consistent regardless of grade level. These findings have critical applications in curriculum development as well as in the classroom. Teachers can use student perceptions of their learning environment to emphasize critical pedagogical approaches and modify other areas that enable enhancement of the science laboratory learning environment.     

A comparison between traditional and constructivist teaching in college biology

Two large sections of introductory biology for nonmajors were given the same course information with two different teaching styles. One group (N=86) was presented material in the traditional teacher-centered manner of lecture and laboratory while course information was given to the second group (N=98) in the student-centered, constructivist format. Learning was assessed in both groups with the same evaluative instruments and the results compared. This analysis revealed that the experimental (constructivist taught) population did significantly better than the control (traditionally taught) population. Furthermore, the students in the experimental group maintained a better attitude throughout the semester and enjoyed the introductory course more than the students in the control population.     

Integrating pharmacology topics in high school biology and chemistry classes improves performance

Although numerous programs have been developed for Grade Kindergarten through 12 science education, evaluation has been difficult owing to the inherent problems conducting controlled experiments in the typical classroom. Using a rigorous experimental design, we developed and tested a novel program containing a series of pharmacology modules (e.g., drug abuse) to help high school students learn basic principles in biology and chemistry. High school biology and chemistry teachers were recruited for the study and they attended a 1‐week workshop to learn how to integrate pharmacology into their teaching. Working with university pharmacology faculty, they also developed classroom activities. The following year, teachers field‐tested the pharmacology modules in their classrooms. Students in classrooms using the pharmacology topics scored significantly higher on a multiple choice test of basic biology and chemistry concepts compared with controls. Very large effect sizes (up to 1.27 standard deviations) were obtained when teachers used as many as four modules. In addition, biology students increased performance on chemistry questions and chemistry students increased performance on biology questions. Substantial gains in achievement may be made when high school students are taught science using topics that are interesting and relevant to their own lives. © 2003 Wiley Periodicals, Inc. J Res Sci Teach 40: 922–938, 2003