Glasenapp, Matthew

Matthew Glasenapp is a graduate student in the Department of Ecology and Evolutionary Biology at the University of California, Santa Cruz. His research focuses on understanding the genetic basis of speciation through investigating how reproductive barriers evolve between closely related species. Matthew participated in the PDP to improve his pedagogy to better serve the students he teaches, hoping to one day become a liberal arts college professor.


Teaching Activity Summary

Name of Teaching ActivityToxicology WEST

Teaching VenueWorkshops for Engineer & Science Transfers, Toxicology Strand (WEST), Sept 2019

Learners: 22 community colleget transfer-students.

Reflection on teaching and assessing the core science or engineering concept:

“The dose makes the poison” is an old adage in the field of toxicology that has led to the common

misconception that dosage and toxicity have a relationship of direct proportionality. Although true in

some cases, this assumption is largely simplistic of true biological processes. Our content goal was for

students to design experiments using toxins and model organisms to investigate the intricacies of the

dose-response relationship in ecologically relevant study systems. Dose-response curves are a core

concept in a broad range of environmental toxicology and medical fields. Understanding the complexity

of dose-response relationship will benefit learners in their classes, research, and own health and nutrition.

Students have numerous difficulties in understanding dose-response curves. Often, they assume the

relationship between dose and toxicity to be linear, failing to consider the possibility of nonlinear

relationships and important biological thresholds. Other common pitfalls include failing to recognize that

different biological organisms may respond in different ways to doses of the same toxin and neglecting to

consider other variables that may influence the dose-response relationship of a single system.

To address these shortcomings, we designed a role-playing activity where students assumed the role of an

Environmental Protection Agency (EPA) scientist tasked with understanding the toxicity of mystery

chemicals on model organisms C. elegans and Daphnia magna. In small groups, students were asked to

design and carry out experiments and report back in a culminating poster session. Students were assessed

on their learning through performance on two different tasks: an individual written response and a group

poster presentation. Towards the end of the activity, students were given a written prompt asking them to

individually describe their understanding of the dose-response relationship after reflecting on the results

of their own experiments as well as the experiments of other groups. In their response, students were

asked to discuss the relative effect of the three mystery chemicals, draw comparisons between toxicity

between the two organisms tested (C. elegans and D. magna), offer implications of their experimental

outcomes, and propose a follow-up experiment. Next, learners were asked to create a collaborative poster

with their experiment group summarizing their experimental design, results, implications, and proposed

follow-up experiment. This was an opportunity for learners to fill in knowledge gaps they may noticed

after writing their individual responses.

To evaluate learners’ performance, we designed a rubric consisting of three dimensions relating to our

core concept. Students did not need to have any prior toxicology knowledge to score high on our rubric.

For each dimension, the highest possible score was a 2, indicating sufficient understanding. A score of 1

signaled misunderstanding or incomplete understanding. Overall, we succeeded in guiding most students

to a sufficient level of understanding of our content goals. Evaluation of both the individual written

response and the group poster allowed us to give a majority of the students’ scores of 2 in all three

dimensions. We did not receive adequate evidence of understanding from several students, highlighting a

few minor flaws in our rubric design. We noticed during evaluation that the language of our assessment

task prompts may have been too vague, leading some students to misunderstand what was expected of

them. These students didn’t necessarily provide incorrect responses, they just missed a few of the key

items we were looking for. If we had to teach this activity again, we would likely adjust the wording of

our assessment task prompts, as our shortcoming was not in our ability to guide learners to the content

goal, but in prompting them to put what they had learned into writing for fair evaluation.