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Code Plagiarism

How to detect copied, reused and refactored source code across student and developer submissions.

All Code Plagiarism AI Detection Academic Integrity Web Plagiarism Code Quality Open Source Licensing Tutorials Case Studies
Do AST-Based Engines Catch More Refactored Cheating Than Token-Based Ones General 10 min
Dr. Sarah Chen Dr. Sarah Chen • 2 months ago

Do AST-Based Engines Catch More Refactored Cheating Than Token-Based Ones

A mid-sized university CS department ran a controlled study comparing AST-based and token-based plagiarism detection across student assignments that had been systematically refactored. The results reveal which technique handles control flow restructuring, identifier renaming, and method reordering — and where both fail entirely.

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How a TA Spots Refactored Code in 300 Java Submissions General 13 min
Priya Sharma Priya Sharma • 2 months ago

How a TA Spots Refactored Code in 300 Java Submissions

Teaching assistants often face the challenge of detecting code plagiarism when students refactor submissions to evade similarity checkers. This article profiles one TA's workflow using AST-based analysis and structural fingerprinting to catch plagiarized code in a large introductory Java course, with practical techniques applicable to any programming educator.

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Why More CS Departments Are Adopting Layered Detection General 10 min
Rachel Foster Rachel Foster • 2 months ago

Why More CS Departments Are Adopting Layered Detection

Computer science departments are discovering that no single detection method catches every kind of code plagiarism. This article explores the layered detection approach combining structural, web-source, and AI analysis to create a comprehensive academic integrity system.

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When Is Peer Similarity Enough in a Plagiarism Checker General 13 min
James Okafor James Okafor • 2 months ago

When Is Peer Similarity Enough in a Plagiarism Checker

Source code plagiarism detection relies on two fundamentally different reference sets: peer submissions and the open web. This article examines the trade-offs between each approach, when one method catches cheating the other misses, and how to build detection strategies that combine both for maximum coverage.

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Can Dev Teams Trust Code Similarity for IP Theft Detection General 8 min
James Okafor James Okafor • 2 months ago

Can Dev Teams Trust Code Similarity for IP Theft Detection

Code similarity analysis has long been a staple of academic integrity enforcement, but enterprises face a harder problem: detecting IP theft, insider leaks, and unlicensed reuse in complex, multi-repo codebases. This post examines the practical limitations and proper applications of similarity detection for proprietary software, from AST comparison to dependency graph analysis.

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The Hidden Plagiarism Your Static Analyzer Is Missing General 7 min
David Kim David Kim • 2 months ago

The Hidden Plagiarism Your Static Analyzer Is Missing

Static analysis tools scan for bugs and smells, but they are blind to a pervasive form of intellectual property theft. Our analysis of 1,200 codebases reveals that 41% contain code plagiarized directly from Stack Overflow, GitHub gists, and commercial tutorials—code often carrying restrictive licenses. This is a legal and integrity blind spot that traditional scanners cannot see.

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The 8 Code Smells That Predict Your Next Plagiarism Case General 3 min
Marcus Rodriguez Marcus Rodriguez • 2 months ago

The 8 Code Smells That Predict Your Next Plagiarism Case

Plagiarism detection often starts long before you upload files to a scanner. Experienced educators recognize specific, subtle anomalies in student code—odd stylistic choices, inconsistent skill levels, and bizarre architectural decisions—that scream "this isn't original work." Here are the eight most reliable human-readable indicators that should trigger a deeper, automated investigation.

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The Assignment That Broke Every Plagiarism Checker General 7 min
James Okafor James Okafor • 3 months ago

The Assignment That Broke Every Plagiarism Checker

Professor Elena Vance thought her data structures assignment was cheat-proof. Then she discovered a student had submitted code that passed MOSS, JPlag, and even Codequiry's initial scan. The incident revealed a new, sophisticated form of code plagiarism that's spreading across computer science departments. This is the story of how one university adapted its entire integrity strategy.

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The Assignment That Broke Every Plagiarism Checker General 8 min
Priya Sharma Priya Sharma • 3 months ago

The Assignment That Broke Every Plagiarism Checker

When a Stanford CS106A professor noticed identical, bizarre logic errors across dozens of student submissions, she uncovered a cheating method no standard tool could catch. This is the story of how students exploited the very algorithms designed to stop them, and what it revealed about the blind spots in automated code similarity detection. The fallout changed how the department thinks about academic integrity.

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The Assignment That Broke Every Plagiarism Checker General 10 min
David Kim David Kim • 4 months ago

The Assignment That Broke Every Plagiarism Checker

A single, brilliantly simple programming assignment exposed a fundamental flaw in how we detect copied code. Students aren't just copying—they're engineering similarity. This deep dive reveals the algorithmic arms race between educators and cheaters, moving beyond token matching to the structural and semantic analysis that actually works.

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