Course-based undergraduate research experiences (CUREs) rapidly have become more common in biology laboratory courses. The effort to implement CUREs has stimulated attempts to differentiate CUREs from other types of laboratory teaching. The Laboratory Course Assessment Survey (LCAS) was developed to measure students' perceptions of how frequently they participate in activities related to iteration, discovery, broader relevance, and collaboration in their laboratory courses. The LCAS has been proposed as an instrument that can be used to define whether a laboratory course fits the criteria for a CURE or not. However, the threshold LCAS scores needed to define a course as a CURE are unclear. As a result, we examined variation in published LCAS scores among different laboratory course types. In addition, we examined the distribution of LCAS scores for students enrolled in our research-for-credit course. Overall, we found substantial variation in scores among CUREs and broad overlap among course types in scores related to all three scales measured by the LCAS. Furthermore, the mean LCAS scores for all course types fell within the main part of the distribution of scores for our mentored research students. These results suggest that the LCAS cannot be used to easily quantify whether a course is a CURE or not. We propose that the biology education community needs to move beyond trying to quantitatively identify whether a course is a CURE. Instead, we should use tools like the LCAS to investigate what students are actually doing in their laboratory courses and how those activities impact student outcomes.
Student self-perception is related to persistence in science. Yet how self-perception de-velops over time is less clear. We examined student self-perception trajectories and their relationship with gender, persons excluded due to ethnicity or race (PEER) status, and first-generation college student (FGCS) status across a yearlong introductory biology se-quence. While we found similar rates of change in self-efficacy and science identity for all groups, females and PEER students had lower initial scores that failed to “catch up” to male and non-PEER scores by the end of the year. Students grouped into either high and stable or lower and decreasing trajectories for scientific community values, with first-generation college students overrepresented in the latter group. Additionally, we found no evidence for intersectionality of subgroups. We did find evidence that the relationship between gender and PEER status and science identity is likely mediated via self-efficacy. Taken together, our results suggest that introductory biology students develop self-efficacy and science identity at similar rates regardless of gender, PEER status, or FGCS status and that interventions targeting scientific community values for all students and self-efficacy of female and PEER students may be fruitful areas to pursue to increase persistence of students in the sciences and to reduce score differences between groups.
Calls for early exposure of all undergraduates to research have led to the increased use and study of course-based research experiences (CREs). CREs have been shown to increase measures of persistence in the sciences, such as science identity, scientific self-efficacy, project ownership, scientific community values, and networking. However, implementing CREs can be challenging and resource-intensive. These barriers may be partly mitigated by the use of short-term CRE modules rather than semester- or year-long projects. One study has shown that a CRE module captures some of the known benefits of CREs as measured by the Persistence in the Sciences (PITS) survey. Here, we used this same survey to assess outcomes for introductory biology students who completed a semester of modular CREs based on faculty research at an R1 university. The results indicated levels of self-efficacy, science community values, and science identity similar to those previously reported for students in the Science Education Alliance-Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) full-semester CRE. Scores for project ownership (content) were between previously reported traditional lab and CRE scores, while project ownership (emotion) and networking were similar to those of traditional labs. Our results suggest that modular CREs can lead to significant gains in student affect measures that have been linked to persistence in the sciences in other studies. Although gains were not as great in all measures as with a semester-long CRE, implementation of modular CREs may be more feasible and offers the added benefits of exposing students to diverse research fields and lab techniques.
Science self-efficacy, a student’s confidence in being able to perform scientific practices, interacts with science identity and outcomes expectations, leading to improved performance in science courses, persistence in science majors, and ultimately, the pursuit of advanced training in the sciences. Inquiry-based laboratory courses have been shown to improve undergraduate student self-efficacy, but the mechanisms involved and specific components of instructional practices that lead to improved self-efficacy are not clear. In the current study, we determined whether student and faculty perceptions of laboratory instructional practices (scientific synthesis, science process skills, and instructor-directed teaching) were related to postsemester self-efficacy across 19 guided-inquiry laboratory courses from 11 different institutions. Self-efficacy related to science literacy increased significantly from the beginning of the semester to the end of the semester. Variation in individual student perceptions of instructional practices within a course were significantly related to differences in student self-efficacy at the end of the semester, but not average student perceptions or faculty perceptions of their own practices across courses. The importance of individual student perceptions suggests that faculty should engage with students during curricular development. Furthermore, faculty need to use noncontent talk to reinforce the science practices students are engaging in during inquiry-based laboratory courses.
Course-based undergraduate research experiences (CUREs) are an effective means of transforming the learning and teaching of science by involving students in the scientific process. The potential importance of the microbiome in shaping both environmental health and disease makes investigations of microbiomes an excellent teaching tool for undergraduate microbiology. Here, we present a CURE based on the microbiome of the bean beetle (Callosobruchus maculatus), a model system for undergraduate laboratory education. Despite the extensive research literature on bean beetles, little is known about their microbiome, making them an ideal system for a discovery-based CURE. In the CURE, students acquire microbiological technical skills by characterizing both culturable and unculturable members of the beetle gut-microbial community. Students plate beetle gut homogenates on different media, describe the colonies that are formed to estimate taxonomic diversity, extract DNA from colonies of interest, PCR amplify the16S rRNA gene for Sanger sequencing, and use the NCBI-nBLAST database to taxonomically classify sequences. Additionally, students extract total DNA from beetle gut homogenates for high-throughput paired-end sequencing and perform bioinformatic and statistical analyses of bacterial communities using a combination of open-access data processing software. Each activity allows students to engage with studies of microbiomes in a real-world context, to apply concepts and laboratory techniques to investigate either student or faculty-driven research questions, and to gain valuable experiences working with large high-throughput datasets. The CURE is designed such that it can be implemented over either 6-weeks (half semester) or 12-weeks (full semester), allowing for flexibility within the curriculum. Furthermore, student-generated data from the CURE (including bacterial colony phenotypic data, full-length 16S rRNA gene sequences from cultured isolates, and bacterial community sequences from gut homogenates) has been compiled in a continuously curated open-access database on the Bean Beetle Microbiome Project website, facilitating the generation of broader research questions across laboratory classrooms.
Previous theoretical work has suggested that females should prefer to mate with older males, as older males should have higher fitness than the average fitness of the cohort into which they were born. However, studies in humans and model organisms have shown that as males age, they accumulate deleterious mutations in their germ-line at an ever-increasing rate, thereby reducing the quality of genes passed on to the next generation. Thus, older males may produce relatively poor-quality offspring. To better understand how male age influences female mate preference and offspring quality, we used a genetic algorithm model to study the effect of age-related increases in male genetic load on female mate preference. When we incorporate age-related increases in mutation load in males into our model, we find that females evolve a preference for younger males. Females in this model could determine a male's age, but not his inherited genotype nor his mutation load. Nevertheless, females evolved age-preferences that led them to mate with males that had low mutation loads, but showed no preference for males with respect to their somatic quality. These results suggest that germ-line quality, rather than somatic quality, should be the focus of female preference in good genes models.
Curricular reform efforts depend on our ability to determine how courses are taught and how instructional practices affect student outcomes. In this study, we developed a 30-question survey on inquiry-based learning and assessment in undergraduate laboratory courses that was administered to 878 students in 54 courses (41 introductory level and 13 upper level) from 20 institutions (four community colleges, 11 liberal arts colleges, and five universities, of which four were minority-serving institutions). On the basis of an exploratory factor analysis, we defined five constructs: metacognition, feedback and assessment, scientific synthesis, science process skills, and instructor-directed teaching. Using our refined survey of 24 items, we compared student and faculty perceptions of instructional practices both across courses and across instructors. In general, faculty and student perceptions were not significantly related. Although mean perceptions were often similar, faculty perceptions were more variable than those of students, suggesting that faculty may have more nuanced views than students. In addition, student perceptions of some instructional practices were influenced by their previous experience in laboratory courses and their self-efficacy. As student outcomes, such as learning gains, are ultimately most important, future research should examine the degree to which faculty and student perceptions of instructional practices predict student outcomes in different contexts.
Over the past decade, repeated calls have been made to incorporate more active teaching and learning in undergraduate biology courses. The emphasis on inquiry-based teaching is especially important in laboratory courses, as these are the courses in which students are applying the process of science. To determine the current state of research on inquiry-based teaching in undergraduate biology laboratory courses, we reviewed the recent published literature on inquiry-based exercises. The majority of studies in our data set were in the subdisciplines of biochemistry, cell biology, developmental biology, genetics, and molecular biology. In addition, most exercises were guided inquiry, rather than open ended or research based. Almost 75% of the studies included assessment data, with two-thirds of these studies including multiple types of assessment data. However, few exercises were assessed in multiple courses or at multiple institutions. Furthermore, assessments were rarely based on published instruments. Although the results of the studies in our data set show a positive effect of inquiry-based teaching in biology laboratory courses on student learning gains, research that uses the same instrument across a range of courses and institutions is needed to determine whether these results can be generalized.
Although we agree with Theobold and Freeman (2014) that linear models are the most appropriate way in which to analyze assessment data, we show the importance of testing for interactions between covariates and factors.
Faculty development workshops are frequently used to bring about change in faculty teaching. Yet, the characteristics of successful faculty professional development in the context of laboratory teaching are unclear. In this Perspective, we describe our approach to intensive hands-on faculty development workshops for fostering change in laboratory teaching and present evidence for the effectiveness of the approach. The outcomes from our workshops and feedback from past participants support the following recommendations: 1) faculty should attend workshops in teams from their institutions, 2) workshops should allow participants to develop curricula that can be implemented with relatively little additional work after the workshop, 3) workshops should allow faculty time to “work” on tangible products and should involve hands-on activities, 4) workshops should be of sufficient duration to allow for faculty to develop expertise and tangible products but short enough that faculty do not “burn out,” and 5) a structure for ongoing and systematic follow-up with participants is essential.