This paper investigates two specific probabilistic biases which middle graders usually exhibit when reasoning about probability and randomness on assessment items. We discuss how students' reasoning about key probability concepts undergirds statistics literacy related to randomness, independence, and the likelihood of future events based on past…

The research shared in this conference paper report illustrates how an iterative process to item development that involves expert review and cognitive lab interviews with students can be used to collect evidence of validity for assessment items. Analysis of students' reasoning was also used to expand a model for identifying conceptions and…