Marcia Cordts, PhD

Associate of Microbiology and Immunology

Contact Information

3-610 Bowen Science Building
51 Newton Rd
Iowa City, IA 52242


BA, Magna Cum Laude, Stephens College
PhD, Microbiology, Cornell University

Research Summary

Since arriving at the University of Iowa in 1997, I have been fortunate to be able to direct all my energies towards microbiology education. My goal has been to develop and utilize the most effective instructional methods through all stages of the learning process, beginning with diverse strategies to engage the student and ultimately achieving meaningful evaluation of students' learning. My classroom strategies fit with the current literature in science education which supports the value of formative assessments (frequent, on-going, non-punitive testing) to facilitate students' construction of subject mastery.

For many years, I have been working to re-envision and broaden the goals of traditional multiple choice testing through a strategy that I call "Test Re-tries". For each Test Re-Try assignment, students are able to earn partial credit after an exam by explaining in a written document the specific problem(s) with each incorrect answer that they made during the exam. After explaining the nature of their incorrect choice, the students revisit the original test to choose the correct answer and briefly write up a sound rationale in support of their second-try answer. Students in all the courses in which I have used Test Re-tries have expressed their satisfaction regarding the fairness and effectiveness of this learning device, and over the years I have noted my broadening abilities to create questions that test higher cognitive levels according to Bloom's levels of understanding (a six-tiered scheme of human conceptualization originally formulated by Benjamin Bloom and colleagues in 1956). While multiple choice tests are frequently employed only for the lowest levels of cognition (e.g., recall or naming), in fact good multiple choice test questions can engage students at higher levels such as application and analysis. However, for students who may equate academic success with rote memorization, higher level questions prove extremely daunting and such students may respond to poor test performance by doubling down on the volume of trivial facts they memorize, or even quitting science. Using Test Re-tries, such students may come to appreciate use of higher order thinking skills to derive real utility from the key facts and names which they have already memorized.

Recently, I have further adapted Test Re-Tries into "No Stress Quizzes" for General Microbiology students. No-Stress Quizzes take place in two parts: an initial, in-class, closed-book multiple choice quiz followed by an open-book written assignment in which each student builds upon his/her responses from the initial quiz. Unlike Test Re-Tries, in these bi-weekly No-Stress Quizzes students receive no grade penalty for the incorrect choices selected during the closed book portion of the quiz. Furthermore, students must write up and hand-in rationales for all questions, both those answered correctly as well as any answered incorrectly during the initial quiz. For example, a student who answered correctly on all five quiz questions initially would write five rationales to explain the reasoning that supported his/her choice of the correct answers, while a student who initially answered incorrectly on all questions on the quiz would be required to write explanations pinpointing the specific fallacy or incongruity underlying each of his/her "wrong" choices as well as justifying a rationale for their second-try answer. Each student in this example may earn full credit for that particular No-Stress Quiz assuming that all rationales are sound and thoughtful (that is, five "correct choice" explanations from the former student and ten explanations for right and wrong choices from the latter student). Based on my experiences in two semesters with nearly two hundred students, I have observed that students seem to appreciate that their ultimate score on No-Stress Quizzes reflects improved critical thinking and a soundly constructed knowledge base. The use of No-Stress Quizzes has allowed me to remove a disadvantage of Test-Re-tries, which is to say that students who enter microbiology class with rote memorization as their basic learning strategy do not necessarily incur a grade penalty.

In addition to my teaching innovations described above, in my classes I strive towards more effective uses of clickers (student response systems), learning objectives, and on-line (iterative) laboratory calculations quizzes. For specific lessons that call for observational and critical thinking skills on the students' parts, I continue to experiment with ways to implement formative assessment via ICON, the courseware that is freely available to all students enrolled at the University of Iowa.