Exception-type confusion was the dominant difficulty pattern in SafeDivide at the University of Houston (90% of incorrect attempts) and persisted across harder problems in both deployments¶

Claim · All claims
Evidence · 1 study (2 entries) · design r2 · q2
Currency · newest study 2026 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? At the University of Houston, exception type confusion affected 90% of students with incorrect attempts on P1 and remained present on P2 (48%) and P3 (37%). → Daniel Prol 2026 q2 i? At Aalto University, 62% of incorrect attempts on safe_integer involved a broad or wrong exception class, and on safe_list (P3) most students with incorrect attempts (89%) selected an incorrect guard condition, reflecting confusion about when to raise. → Daniel Prol 2026 (2)

Evidence¶

Daniel Prol 2026¶

Daniel Prol, Juho Leinonen, Arto Hellas, Saleh Alkhamees, Amin Alipour. (2026). Pulla: A Parsons Problem Tool for Fine-Grained Behavioral Tracing and Instructor-Facing Problem-Solving Analysis. arXiv. https://arxiv.org/abs/2609.15944 doi:10.48550/arxiv.2609.15944

q2 · i? · design · r2

Log analysis of UH deployment attempts across the three Parsons problems. Trace data show "exception type confusion was the dominant pattern in P1, affecting 90% of students with incorrect attempts", with students placing semantically imprecise types where a more specific subtype was required.

"At the University of Houston, exception type confusion was the dominant pattern in P1, affecting 90% of students with incorrect attempts, and remained present in P2 (48%) and P3 (37%): in each case students placed a semantically imprecise type, such asIllegalStateException, Exception, or RuntimeException, where a more specific subtype was required."

Daniel Prol 2026 (2)¶

Daniel Prol, Juho Leinonen, Arto Hellas, Saleh Alkhamees, Amin Alipour. (2026). Pulla: A Parsons Problem Tool for Fine-Grained Behavioral Tracing and Instructor-Facing Problem-Solving Analysis. arXiv. https://arxiv.org/abs/2609.15944

q2 · i? · design · r2

Log analysis of Aalto deployment attempts on the safe_list problem. The trace data show "most students with incorrect attempts (89%) selected an incorrect guard condition", choosing if index < 0 rather than the correct bound, which the authors read as confusion about when rather than which exception to raise.

"in safe_list (P3), most students with incorrect attempts (89%) selected an incorrect guard condition. The dominant error in P3 was choosing if index < 0 rather than the correct bound if index < -len(items) , which is required to reject out-of-range negative indices."

Discussion¶

Related Claims¶

• Control-flow ordering errors appeared across all UH problems (43–52% of incorrect attempts) but were only a secondary pattern at Aalto, with the conceptual barrier apparently shifting with problem structure — related
• Students across both deployments substituted return statements for exception-raising constructs, treating error conditions as reasons to exit early — related
• Deploying a trace-capturing Parsons tool in two university courses surfaced recurring difficulty patterns including exception-type misidentification, return-for-throw confusion, and incorrect control-flow ordering — a broader claim this one bears on
• State revisits within solving sessions were rarer in the Pulla deployments (6–12% of UH sessions, 0–3% at Aalto) than the 21–33% previously reported for similar Parsons tasks — related
• Students struggle with the 'not' operator and logical operator precedence when evaluating conditional statements — related