Mahdi Molavi | Senior Backend Engineer & Tensor Researcher https://mahdimolavi.ir/ en Mahdi Molavi | Senior Backend Engineer & Tensor Researcher DataLife Engine IRT Calibration Notes 6: Equal Sample Sizes Are Not Equating https://mahdimolavi.ir/backend-notes/81-irt-calibration-notes-6-equal-sample-sizes-are-not-equating.html https://mahdimolavi.ir/backend-notes/81-irt-calibration-notes-6-equal-sample-sizes-are-not-equating.html IRT Calibration Notes 6: Equal Sample Sizes Are Not Equating

Equal N per track made year-to-year IRT comparisons more controlled, once a subtopic-key bug that hid 13 of 30 questions was fixed. Bar charts, boxplots, item information ranks and the scale-linking problem show why equal sample sizes are still not equating.

]]> admin Wed, 28 Oct 2026 10:00:00 +0330 IRT Calibration Notes 5: Twenty Samples per Size in a Reproducible Sampling Study https://mahdimolavi.ir/backend-notes/79-irt-calibration-notes-5-reproducible-repeated-sampling-study.html https://mahdimolavi.ir/backend-notes/79-irt-calibration-notes-5-reproducible-repeated-sampling-study.html IRT Calibration Notes 5: Twenty Samples per Size in a Reproducible Sampling Study

A nine-exam repeated-sampling study of IRT discrimination, built to be reproducible and restartable. It covers nested samples from deterministic seeds, fit keys that expose reused fits, atomic checkpoints and paired tests with Benjamini-Hochberg control.

]]> admin Tue, 27 Oct 2026 10:00:00 +0330 Backend Notes 4: PDF to LaTeX with an LLM in the Loop https://mahdimolavi.ir/backend-notes/29-backend-notes-4-pdf-to-latex-llm-question-bank.html https://mahdimolavi.ir/backend-notes/29-backend-notes-4-pdf-to-latex-llm-question-bank.html Backend Notes 4: PDF to LaTeX with an LLM in the Loop

Turning written exams into more than 5,000 structured, database-ready questions: extraction, LaTeX conversion, compile checks, LLM tagging of topic, skill and difficulty with a JSON schema, and why a human review console stays in the loop.

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