Students across both deployments substituted return statements for exception-raising constructs, treating error conditions as reasons to exit early¶

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, 60% of students with incorrect attempts on SafeDivide (P1) placed a return statement rather than throwing an exception, and 47% substituted return for throw on P3. → Daniel Prol 2026 q2 i? At Aalto University, 50% of students with incorrect attempts on safe_integer (P2) substituted return for raise ValueError, treating a parse failure as a silent exit. → 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 on the SafeDivide and CheckedVsUnchecked Parsons problems. The trace data show "60% of students with incorrect attempts placed if (b == 0) return 0" instead of throwing, and 47% substituted return for throw on P3.

"At the University of Houston (𝑛= 68), 60% of students with incorrect attempts placed if (b == 0) return 0 in SafeDivide (P1) rather than throw new ArithmeticException(. . . ) , and 47% substitutedreturn for throw in CheckedVsUnchecked (P3)."

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 the Aalto CS1 deployment on the safe_integer Parsons problem. Among students with incorrect attempts, "50% of students with incorrect attempts substituted return for raise ValueError", which the authors interpret as treating the error as a silent exit rather than an exceptional event.

"At Aalto University, this pattern was prominent insafe_integer (P2), where 50% of students with incorrect attempts substituted return for raise ValueError , treating a parse failure as a silent exit rather than an exceptional event."

Discussion¶

Related Claims¶

• 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 — 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
• 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
• 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
• Student specification comments are predominantly natural language, except Return statements which show a high proportion of Strict-Code expressions — related