Back to PACER

Release history

Changelog

Every version of PACER, documented. Named releases mark major milestones.

🤖
Local AI Assistant
Gemma 4 Billion runs entirely on-device within the PACER Desktop app, powering an AI assistant for guidance and interpretation of psychometric results. No data leaves your machine. This feature is exclusive to the Windows desktop client — the web application is unaffected.
Windows desktop
AI Assistant Gemma 4B On-Device Desktop Only
📊
Item Analysis
Classical test theory statistics including p-values, point-biserial correlations, distractor analysis, and reliability estimates.
⚙️
Item Calibration
Full IRT calibration engine supporting 1PL, 2PL, 3PL, GRM, GPCM, PCM, and RSM via marginal maximum likelihood with EM and Gauss-Hermite quadrature.
🎯
Scoring
IRT-based ability estimation with EAP, MAP, and MLE methods. Full support for polytomous and mixed-format tests.
🧩
Cognitive Diagnostic Models
DINA, DINO, and G-DINA calibration and scoring for diagnostic classification and skill mastery profiling.
🔗
Equating & Linking
Six equating methods including Stocking-Lord, Haebara, Mean/Sigma, and Mean/Mean for linking test forms to a common scale.
🏗️
Test Construction & Assembly
Automated test assembly powered by Google OR-Tools CP-SAT solver. Blueprint constraints, TIF optimization, item groups, and simultaneous multi-form assembly.
🔍
DIF Analysis
Differential item functioning detection using Mantel-Haenszel and standardized mean difference statistics across focal and reference groups.
👥
Multigroup Calibration
Bock-Zimowski multigroup IRT for concurrent calibration across multiple populations with group-specific ability distributions.
Web application
Windows desktop
REST API
IRT CDM CTT DIF Equating Test Assembly Multigroup PDF Reports PACER University