A method for assessing and describing the informal inferential reasoning of middle school students

Informal Inferential Reasoning (IIR) has emerged in the last decade in the study of statistics education. Developing students' IIR ability is seen as a way of preparing students for the important topic of Formal Statistical Inference (FSI); however, research is still needed in order to investigate how students transition between informal and formal statistical reasoning. A primary difficulty is that we do not have a way of assessing and describing students' IIR ability levels. In order to address this, an Assessment of Informal Inferential Reasoning (AIIR) was developed, along with a Structure of Observed Learning Outcomes (SOLO) taxonomy (Biggs & Collis, 1982) adaptation focusing on describing students' IIR abilities. Results of the research show that for the age range investigated, the AIIR and SOLO taxonomy adaptation reliably identified and classified students' IIR abilities.