Time spent on active learning activities does not necessarily correlate with student exam performance: a controlled case study.

Active learning, including student thinking and discussion in class, has been shown to increase student learning gains. However, it is less clear how instructor-level variation in the implementation and timing of active learning activities affects student gains. Our study aims to investigate the extent to which the time spent on individual episodes of active learning activities influences student performance. We hypothesized that instructors who let students spend more time on peer discussion and individual thinking on practice problems associated with particular learning objectives would have better student exam scores on exam questions addressing those objectives. To test this hypothesis, we obtained a large data set of classroom recordings and student exam scores from an introductory biology course at a large 4-year university, where three instructors shared identical teaching materials and exams for different course offerings. Contrary to our hypothesis, although the three instructors spent significantly different amounts of time on episodes of thinking and peer discussion, there was no correlation between the total time spent on active learning activities and student performance on exam questions. Linear mixed-effects modeling of the effect of the length of episodes of student thinking and discussion on exam score found that in the context of shared instructional materials, the amount of course time spent on active learning activities did not reliably predict student performance on associated exam questions. This result held true even when only considering learning objectives with high variations in performance between offerings, difficult exam questions, or exam questions requiring higher-order thinking skills. Although our study was only conducted in one course, our results imply that time spent per individual episode of student thinking or peer discussion may not be the primary factor explaining the positive effects of active learning and that it may be worthwhile to explore other factors.

Chronic shedding of a SARS-CoV-2 Alpha variant in wastewater.

BACKGROUND: Central Michigan University (CMU) participated in a state-wide SARS-CoV-2 wastewater monitoring program since 2021. Wastewater samples were collected from on-campus sites and nine off-campus wastewater treatment plants servicing small metropolitan and rural communities. SARS-CoV-2 genome copies were quantified using droplet digital PCR and results were reported to the health department. RESULTS: One rural, off-campus site consistently produced higher concentrations of SARS-CoV-2 genome copies. Samples from this site were sequenced and contained predominately a derivative of Alpha variant lineage B.1.1.7, detected from fall 2021 through summer 2023. Mutational analysis of reconstructed genes revealed divergence from the Alpha variant lineage sequence over time, including numerous mutations  in the Spike RBD and NTD. CONCLUSIONS: We discuss the possibility that a chronic SARS-CoV-2 infection accumulated adaptive mutations that promoted long-term infection. This study reveals that small wastewater treatment plants can enhance resolution of rare events and facilitate reconstruction of viral genomes due to the relative lack of contaminating sequences.