Program Behavior Gaps: An Extension of the Rules of Program Behavior Framework

Jesse Hoobergs; Tom Schrijvers; Felienne Hermans

doi:10.1145/3796523

Program Behavior Gaps: An Extension of the Rules of Program Behavior Framework

Jesse Hoobergs^*
, Tom Schrijvers
, Felienne Hermans

^*Corresponding author for this work

Research output: Contribution to Journal › Article › Academic › peer-review

Abstract

The Rules of Program Behavior framework notes that teachers target a model of program behavior instead of the complex semantics of the programming language, and allows describing these models as sets of rules of program behavior. When learners execute code, its behavior is defined by the semantics of the programming language, which might differ from the targeted model of program behavior. In this article, we present a theoretical framework that builds on the Rules of Program Behavior framework, while giving a more prominent role to the differences between the targeted models and the programming language semantics. We call these differences Program Behavior gaps and distinguish between incompleteness gaps—untaught parts—and conflict gaps—a semantic rule that conflicts with a rule of program behavior—, and between transparent and opaque gaps. Visualizations of the relation between the semantics of the programming language and the targeted model of program behavior are an integral part of our framework as they allow visualizing the gaps that could exist in a code fragment and whether these gaps are activated or not. On top of this, the framework contains clear definitions to distinguish between valid conceptions, misconceptions, missing conceptions, prior conceptions, fluid conceptions and program behavior gaps. The framework can be used to devise programming courses, to investigate the mental model of learners and to make a case for gradually evolving languages that are designed to have fewer program behavior gaps. To illustrate this, we (1) present a real-life progression of models of program behavior and discuss, for this progression, the program behavior gaps in 21 code fragments, and (2) present a study grounded in our theoretical framework in which we determine the mental model of each participant.

Original language	English
Article number	50
Pages (from-to)	1-67
Number of pages	67
Journal	ACM Transactions on Computing Education
Volume	26
Issue number	3
Early online date	21 Apr 2026
DOIs	https://doi.org/10.1145/3796523
Publication status	E-pub ahead of print - 21 Apr 2026

Bibliographical note

Publisher Copyright:
© 2026 Copyright held by the owner/author(s).

Funding

This research was partly funded by the KU Leuven Industrial Research Fund (project Grant #3E230056) and the FWO(project Grant #G0A9423N) We thank Tom Holvoet for allowing us to conduct the empirical study in his course. The first authorthanks the participants and mentors of the Koli Calling ’23 Doctoral Consortium for the fruitfuldiscussions that have inspired and crystallized the ideas presented in this article. It was also during aKoli Calling ’23 poster presentation that Otto Seppälä referred the first author to the RPB framework,which was instrumental for this work, and for which the first author is very grateful. Lastly, wewould like to thank the reviewers, both those of an earlier rejected submission to Koli Calling ’24,and those of this TOCE paper. Particular gratitude has to be expressed towards Reviewer 3 of this TOCE paper whose elaborate comments, critiques, and suggestions have undoubtedly improvedthe quality of this article.

Funders	Funder number
Fonds Wetenschappelijk Onderzoek
KU Leuven Industrial Research Fund	3E230056

Keywords

conceptions
instructional design
introductory programming
learning objectives
mental models
model of program behavior
notional machines
program behavior gaps
Programming education
rules of program behavior
semantics

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10.1145/3796523

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Cite this

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Program Behavior Gaps: An Extension of the Rules of Program Behavior Framework

Abstract

Bibliographical note

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Keywords

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