<![CDATA[This study investigated students’ informal inferential reasoning (IIR) levels when interpreting and comparing box plots. This case study purposively selected 36 grade 9 students from a public secondary school in Bangkok, and 29 complete worksheets were analyzed. Using content analysis, the responses were iteratively coded using Pfannkuch’s four levels of IIR (levels 0-3). Responses were distributed across all four levels, predominantly at levels 2 and 3. Level 0 responses identified single values without comparing distributions, while level 1 responses relied on everyday visual descriptions with limited statistical evidence. Level 2 responses justified conclusions using a single distributional feature, whereas level 3 responses coordinated multiple distributional features but often reflected area-represents-frequency-schema heuristics. Instructional design should emphasize integrating multiple distributional features to strengthen reasoning. These findings provide guidance for supporting students’ IIR through box plot instruction.]]>
Copyrights © 2026
