Semih Caglar

Publications

Research papers and competition results I've co-authored.

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SERSEM: Selective Entropy-Weighted Scoring for Membership Inference in Code Language Models

K. K. Dikici, S. Kara, S. Çağlar, E. Tüzün, S. Sav

ACM International Conference on the Foundations of Software Engineering / AI-powered Software (FSE/AIware), 2026· Poisoned Chalice Competition · 1st Place

Abstract

As Large Language Models (LLMs) for code increasingly utilize massive, often non-permissively licensed datasets, evaluating data contamination through Membership Inference Attacks (MIAs) has become critical. We propose SERSEM (Selective Entropy-Weighted Scoring for Membership Inference), a novel white-box attack framework that suppresses uninformative syntactical boilerplate to amplify specific memorization signals. SERSEM utilizes a dual-signal methodology: first, a continuous character-level weight mask is derived through static Abstract Syntax Tree (AST) analysis, spellchecking-based multilingual logic detection, and offline linting. Second, these heuristic weights are used to pool internal transformer activations and calibrate token-level Z-scores from the output logits. Evaluated on a 25,000-sample balanced dataset, SERSEM achieves a global AUC-ROC of 0.7913 on the StarCoder2-3B model and 0.7867 on the StarCoder2-7B model, consistently outperforming the implemented probability-based baselines Loss, Min-K% Prob, and PAC. Our findings demonstrate that focusing on human-centric coding anomalies provides a significantly more robust indicator of verbatim memorization than sequence-level probability averages.

Automated Classification of Human Code Review Comments with Large Language Models

S. Çağlar, Ş. E. Gökırmak, E. Tüzün

International Conference on Evaluation and Assessment in Software Engineering (EASE), 2026· CORE A

Abstract

Context: Code reviews are essential for maintaining software quality, yet many human review comments suffer from issues such as redundancy, vagueness, or lack of constructiveness. These types of comments may slow down feedback and obscure important insights. Prior work on code review comments mostly explore the detection and categorization of useful comments, while fine-grained categorization of comment issues remains underexplored. Objective: This work aims to design and evaluate an automated system for classifying code review comments according to specific categories of issues. Methodology: We introduced a nine-label taxonomy for code review comments, covering six review comment smells and three common useful intents, and manually labeled 448 comments from a publicly available dataset. We benchmarked zero-shot and one-shot single-label classification over each comment and its associated unified diff hunk, comparing GPT-5-mini, LLaMA-3.3, and DeepSeek-R1. We reported macro-F1 as the primary metric. Results: Zero-shot performance was moderate under class imbalance (macro-F1 0.360 to 0.374). One-shot exemplar conditioning had model-dependent effects: GPT-5-mini and DeepSeek-R1 macro-F1 scores improved, however LLaMA-3.3 suffered a slight decrease. Exemplars most consistently helped intent-boundary labels, whereas classification of evidence-sensitive labels remain challenging. Conclusion: Our results indicate that comment–diff evidence is sufficient for some labels but limited for evidence-sensitive smells. Future work includes adding thread context, improving intent-preserving rewrites, and validating robustness across platforms.

Automated Inline Comment Smell Detection and Repair with Large Language Models

H. K. Çağlar, S. Çağlar, E. Tüzün

IEEE/ACM International Conference on Automated Software Engineering (ASE), 2025· CORE A* · pp. 1008–1019

Abstract

Context: Code comments play a critical role in improving code readability, maintainability, and collaborative development. However, comments may deviate from best practices due to software evolution, where code changes are not reflected in comments, as well as practitioner-related issues such as vague descriptions, redundancy, or misaligned intent. These issues lead to various comment smells that degrade software quality. While prior studies have explored comment inconsistencies, most are limited in scope, either addressing a narrow subset of smells or focusing solely on detection without considering repair. Objective: This study evaluates the effectiveness of large language models (LLMs) in both detecting and repairing inline code comment smells, using a comprehensive taxonomy of code comment smell types. Method: We extended a prior data set by incorporating repaired versions of smelly comments, resulting in 2,211 unique instances. Four LLMs—GPT-4o-mini, o3-mini, DeepSeek-V3, and Codestral-2501—are evaluated under zero-shot and few-shot prompting strategies. To account for non-deterministic behavior in LLM outputs and ensure robustness, each configuration is executed five times. Detection performance is measured using accuracy, macro F1 score, and Matthews correlation coefficient (MCC); repair is evaluated using SBERT similarity, METEOR, and ROUGE-L. Our multi-stage pipeline feeds detection outputs into the repair phase, where the detection result with the highest macro F1 score is used to simulate the best possible repair scenario. Median scores across runs are reported for comparison. Results: o3-mini with few-shot prompting achieves the highest median detection performance: macro F1 of 0.41, MCC of 0.50, and accuracy of 0.72, exceeding the baseline of GPT-4. For repair, Codestral-2501 in the zero-shot setting yields the best results with a median SBERT score of 0.61, followed by DeepSeek-V3 and GPT-4o-mini at 0.53, and o3-mini at 0.46. Few-shot prompts improve detection, while zero-shot prompts are more effective for repair. Conclusion: Lightweight LLMs such as o3-mini can achieve strong detection performance when guided by effective few-shot prompts. In contrast, repair tasks benefit more from zero-shot prompting, though they introduce challenges such as overfitting and the risk of generating new smells. Our findings support the development of practical tools, including a GitHub-integrated comment repair assistant, and motivate future work on dynamic prompt selection and multilingual benchmark construction.

ATIBA: Grounded Integrity and Quality Checking for Research Papers

V. Karakaya*, S. Çağlar*, Y. Y. Korkmaz*, E. Tüzün

International Workshop on Automated Techniques for Integrity and Quality in Software Engineering Research (ATIQSER), 2026· *Equal contribution

Abstract

Checking a manuscript's reference integrity, its compliance with a target venue's specific submission rules, and its adherence to community reporting standards is manual, repetitive, and different for every venue so in practice it is done inconsistently or skipped. We present ATIBA, a tool that runs five grounded integrity and quality checks on a manuscript: a reference-integrity check that verifies each citation against bibliographic sources and flags retracted or unfindable references; a venue/track compliance check that derives submission criteria directly from a venue's own call-for-papers page and evaluates the manuscript against them, each verdict anchored to a verbatim quote from that page; an empirical-standards compliance check against the ACM SIGSOFT Empirical Standards, with a hallucination defence that discards any evidence quote it cannot locate verbatim in the manuscript; a multi-mode AI review (venue-specific, formal, and page-anchored annotation) powered by GPT-5.4 through Azure OpenAI; and a citation-suggestion feature that proposes candidate references for a manuscript and verifies each against bibliographic sources before it is shown to the user. All five checks are designed around the same principle: an LLM is only trusted to judge, never to invent the evidence it judges against. We evaluated ATIBA through a moderated user study with 13 non-author participants. Agreement across the six survey items ranged from 69% to 92%, with a mean of 85%, providing initial evidence of positive perceived usefulness across the evaluated workflows. These findings establish perceived usefulness; objective accuracy remains to be measured.