miscon:programming.variables.assignment-is-equation · draft · trust low · v0.1.1 · kind misapplied-analogy

Assignment states an equation

The equals sign in an assignment states that the two sides are equal, as in algebra, so x = x + 1 is a contradiction and a = b and b = a mean the same thing.

Stable URI: https://open-misconceptions.github.io/miscon-data/m/programming.variables.assignment-is-equation
UUID: 1d678f7e-ebf2-49bf-979f-eb433148cc0e
Domain: programming.variables
Level band: secondary, undergraduate, adult
Locale: en
About: https://open-misconceptions.github.io/miscon-data/c/programming.variables.assignment (Miscon)

Evidence patterns

Pattern 0: trace an assignment whose right-hand side uses the variable being assigned

declares the statement impossible or leaves the variable unchanged

Item

x = 5
x = x + 1
What is x?

Expected6

Response'Impossible, x can't equal x + 1' (or 5)

Pattern 1: trace an assignment with the variables in the 'wrong' order

treats a = b as also setting b from a, or asks which one changes

Item

a = 1
b = 2
a = b
What are a and b?

Expecteda is 2, b is 2

Responsea is 1, b is 1 (or 'they are now the same variable')

Discriminators

vs a slip. Consistent across items; the learner uses the words 'equals' or 'is the same as' and objects to x = x + 1. A slip is a wrong final value with an otherwise correct trace.

vs programming.variables.assignment-links-variables. Linkers accept a = b as directional but expect later changes to b to show up in a; equation believers object at the moment of assignment.

vs programming.variables.assignment-moves-value. Movers empty the source variable; equation believers keep both sides equal.

Relations

conflicts_with: Assignment copies a value into a variable at one moment (external)
resolved_by: Assignment copies a value into a variable at one moment (external)
confusable_with: programming.variables.assignment-links-variables
programming.variables.assignment-moves-value

Alignments

progmiscon Java/AssignCompares (close-match)
progmiscon's entry covers reading = as a comparison; this record covers the underlying algebraic reading.

Provenance

Origin: llm-drafted

du Boulay, B. (1986). Some difficulties of learning to program. Journal of Educational Computing Research, 2(1), 57-73. doi:10.2190/3LFX-9RRF-67T8-UVK9
Notional machine difficulties; the equals sign carrying its mathematical meaning.
Sorva, J. (2012). Visual Program Simulation in Introductory Programming Education (Doctoral dissertation, Aalto University). Appendix A catalogues introductory programming misconceptions from the literature. link
Qian, Y., & Lehman, J. (2017). Students' misconceptions and other difficulties in introductory programming: A literature review. ACM Transactions on Computing Education, 18(1), Article 1. doi:10.1145/3077618
Chiodini, L., Moreno Santos, I., Gallidabino, A., Tafliovich, A., Santos, A. L., & Hauswirth, M. (2021). A curated inventory of programming language misconceptions. In Proceedings of the 26th ACM Conference on Innovation and Technology in Computer Science Education (ITiCSE '21), 380-386. doi:10.1145/3430665.3456343
Inventory consulted for the misconception name and scope only; progmiscon publishes no licence for its text, so Open Misconceptions' statements and examples are written independently.

Drafted from the cited literature for the Open Misconceptions seed pack; statement, examples and discriminators are original text. Awaiting maintainer review.

Review status

Status draft, trust low (computed from the reviews below against the reviewer registry).

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Formats

Raw JSON
CASE 1.1 package (CFItem 1d678f7e-ebf2-49bf-979f-eb433148cc0e)
Source on GitHub

Cite

miscon:programming.variables.assignment-is-equation
https://open-misconceptions.github.io/miscon-data/m/programming.variables.assignment-is-equation