Fact Sheet
PACER
www.paceronline.com
Dr. Harold Doran, Developer
Independent Product
10
10+
Analysis Capabilities
2
2
Platforms
4
4
Learning Resources
∞
∞
Items Supported
Overview

PACER is a professional-grade web-based platform for psychometric analysis and item response theory calibration. Designed for researchers, assessment developers, and testing organizations, it supports the full analytical workflow — from data import and model calibration through scoring, equating, and reporting.

PACER is an independent product developed by Dr. Harold Doran, a psychometrician with deep expertise in IRT estimation, large-scale assessment, and statistical computing. It is not affiliated with any university or institution.

Mission & Vision
Mission
To provide psychometricians and assessment professionals with a powerful, accurate, and accessible platform for the full IRT analysis workflow — without sacrificing statistical rigor.
Vision
To be the modern standard in psychometric software — powerful enough for research, fast enough for production, and intuitive enough that practitioners never have to fight the tool.
Basic Information
DeveloperDr. Harold Doran — Psychometrician
IndustryPsychometrics, Educational Measurement, Assessment
AffiliationIndependent — not affiliated with any university or institution
PlatformsWeb application (www.paceronline.com) and Windows desktop installer
TrialTime-limited trial available upon request via www.paceronline.com
Capabilities
01IRT Calibration — dichotomous and polytomous modelsIRT
02Multigroup IRT CalibrationIRT
03Cognitive Diagnostic Modeling (CDM)CDM
04Test Equating and LinkingEquating
05Item and Test Information FunctionsIRT
06Population Parameter Estimation with Anchored Item CalibrationIRT
07Differential Item Functioning (DIF) AnalysisIRT
08Classical Item Analysis — p-values, point-biserials, Cronbach's α, SEMIRT
09IRT Scoring — MLE, MAP, EAP, and TCC ability estimationIRT
10Automated Test Assembly (ATA) — blueprint constraints, enemy sets, TIF band optimization via OR-Tools CP-SATTCA
Technology

PACER is built on a .NET / C# backend (ASP.NET minimal API) with a React frontend. The web application is deployed on Microsoft Azure in the United States. A native Windows desktop application is also available as a distributable installer built with Electron. Automated test assembly is powered by Google OR-Tools (CP-SAT solver).

.NET / C# React Microsoft Azure Electron Google OR-Tools
Learning & Support
PACER University Six interactive lessons organized into Beginner, Intermediate, and Advanced tracks — covering Item Analysis, IRT Calibration, IRT Scoring, CDM, Skill Profiling, and Equating — each with live charts, worked examples, and a direct link to the corresponding PACER tool.
Technical Reference Full mathematical notation and methodology documentation rendered in-app with MathJax — always accessible alongside analysis.
Template Library Every accepted file format documented with downloadable templates and field-by-field specifications for data preparation.
API Reference Complete REST API documentation covering all endpoints, request/response schemas, code examples (cURL, C#, JavaScript), and advanced guides for multigroup calibration, anchored item calibration, and polytomous model selection. Available upon request.
Contact
Website www.paceronline.com
Developer Dr. Harold Doran
Inquiries Contact via www.paceronline.com