The Elements of Item Response Theory and its Framework in Analyzing Introductory Astronomy College Student Misconceptions. I. Galaxies

摘要

This is the first in a series of papers that analyze college student beliefsin realms where common astronomy misconceptions are prevalent. Data wascollected through administration of an inventory distributed at the end of anintroductory college astronomy course. In this paper, we present the basicmathematics of item response theory (IRT), and then we use it to exploreconcepts related to galaxies. We show how IRT determines the difficulty of eachgalaxy topic under consideration. We find that the concept of galaxy spatialdistribution presents the greatest challenge to students of all the galaxytopics. We also find and present the most logical sequence to teach galaxytopics as a function of the audience's age.