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CONTEXT The success of QuickCheck has led to the development of property-based testing (PBT) libraries for many languages and the process is getting increasing attention. However, unlike regular testing, PBT is not widespread in collegiate curricula. Furthermore, the value of PBT is not limited to software testing. The growing use of formal methods in, and the growth of software synthesis, all create demand for techniques to train students and developers in the art of specification writing. We posit that PBT forms a strong bridge between testing and the act of specification: it’s a form of testing where the tester is actually writing abstract specifications. INQUIRY Even well-informed technologists mention the difficulty of finding good motivating examples for its use. We take steps to fill this lacuna. APPROACH & KNOWLEDGE We find that the use of “relational” problems—those for which an input may admit multiple valid outputs—easily motivates the use of PBT. We also notice that such problems are readily available in the computer science pantheon of problems (e.g., many graph and sorting algorithms). We have been using these for some years now to teach PBT in collegiate courses. GROUNDING In this paper, we describe the problems we use and report on students’ completion of them. We believe the problems overcome some of the motivation issues described above. We also show that students can do quite well at PBT for these problems, suggesting that the topic is well within their reach. In the process, we introduce a simple method to evaluate the accuracy of their specifications, and use it to characterize their common mistakes. IMPORTANCE Based on our findings, we believe that relational problems are an underutilized motivating example for PBT. We hope this paper initiates a catalog of such problems for educators (and developers) to use, and also provides a concrete (though by no means exclusive) method to analyze the quality of PBT. 

Flawed problem comprehension leads students to produce flawed implementations. However, testing alone is inadequate for checking comprehension: if a student develops both their tests and implementation with the same misunderstanding, running their tests against their implementation will not reveal the issue. As a solution, some pedagogies encourage the creation of input-output examples independent of testing-but seldom provide students with any mechanism to check that their examples are correct and thorough. We propose a mechanism that provides students with instant feedback on their examples, independent of their implementation progress. We assess the impact of such an interface on an introductory programming course and find several positive impacts, some more neutral outcomes, and no identified negative effects. 

Instructors routinely use automated assessment methods to evalu- ate the semantic qualities of student implementations and, some- times, test suites. In this work, we distill a variety of automated assessment methods in the literature down to a pair of assessment models. We identify pathological assessment outcomes in each model that point to underlying methodological flaws. These the- oretical flaws broadly threaten the validity of the techniques, and we actually observe them in multiple assignments of an introduc- tory programming course. We propose adjustments that remedy these flaws and then demonstrate, on these same assignments, that our interventions improve the accuracy of assessment. We believe that with these adjustments, instructors can greatly improve the accuracy of automated assessment. 

This paper presents a lightweight process to guide error report authoring. We take the perspective that error reports are really classifiers of program information. They should therefore be subjected to the same measures as other classifiers (e.g., precision and recall). We formalize this perspective as a process for assessing error reports, describe our application of this process to an actual programming language, and present a preliminary study on the utility of the resulting error reports.