Monday, August 3, 2009

PS 11-101: Diagnostic question clusters: Assessing student understanding of population dynamics, and evaluating effectiveness of a college laboratory activity addressing the topic

Miranda A. Kearney and Nancy E. Stamp. State University of New York - Binghamton

Background/Question/Methods

Student comprehension about concepts of population ecology is imperative to the overall understanding of numerous important issues that currently affect human society. Many students harbor misconceptions about these concepts; thus, it is crucial for instructors to both identify and correct these misunderstandings. In this study we assessed the knowledge of students in a college level introductory biology class (N= approx. 250) before and after a laboratory activity focused on population dynamics.  
Results/Conclusions

We found the following to be the three most prominent misconceptions held by the students:
1.    Carrying capacity does not change
2.    Populations increase until limits are reached, then they crash and go extinct.
3.    Populations exist in states of either constant growth or decline depending upon their position in a food chain.
In addition, we found that the laboratory activity administered to the students did little to challenge and correct these misconceptions. The results from our assessments helped us to design a new activity that focused directly on addressing the misconceptions.