Xcalibre™ 4 represents the leading edge in software for item response theory (IRT) analysis of assessment data. Xcalibre™ 4 calibrates your test using 4 dichotomous and 5 polytomous IRT models, and produces professional reports summarizing the analysis, complete with embedded graphics and tables to facilitate data interpretation. Xcalibre™ 4 is the most user-friendly comprehensive IRT software available; no more DOS command code.

Xcalibre 4 offers several substantial advantages over Xcalibre 1.1:

1. Superior output: save time by utilizing the rich text file (RTF) format prepared as a formal report with embedded tables and graphics, rather than having to build your own report manually. Graphics include the item response function (IRF), the item information function (IIF), the test information function (TIF), and conditional standard error of measurement (CSEM), and numerous frequency distributions. In addition, you can also overlay the empirical fit line with the IRF.
2. More models: Dichotomous models include the 3PL, 2PL, 1PL, and Rasch models. Five polytomous models (below) are also included, plus you are allowed to mix the models for mixed-format tests.
3. Screening: automatically screen out items with unacceptable classical statistics before performing the IRT item parameter calibration.
4. Custom flagging: customize item flagging rules by specifying acceptable ranges and your own flag labels.
5. Produces spreadsheets: easily import results into test development software because statistics are saved as a comma-separated value (CSV) format, which is also able to be easily manipulated (sorted, highlighted, etc.) in spreadsheet software.
6. More theta estimates: can now be produced for multiple domains as well as the full test.
7. Mastery testing: automatically implement cutscores for criterion-referenced tests.
8. More items: analyze up to 1,200 items at once.
9. Pilot/pretest items: compute classical statistics for pretest (pilot or unscored) items to be used for item evaluation.
10. Multiple runs (batch): utilize a “batch” type of capability, to allow you to run multiple data sets without having to use the graphic user interface for each run.

IRT Models

Xcalibre calibrates the following IRT models:
- 3-parameter dichotomous model, ideal for multiple choice data
- 2-parameter dichotomous model, ideal for personality data
- 1-parameter dichotomous model, with equivalent item discriminations
- Rasch dichotomous model, scaled to items rather than people
- Rasch rating scale model (RRSM, or RSM)
- Rasch partial credit model (RPCM, or PCM)
- Generalized rating scale model (GRSM)
- Generalized partial credit model (GPCM)
- Samejima's Graded response model (SGRM, or GRM)

Moreover, you are allowed to utilize both a dichotmous and polytomous model at once. For example, if your test has 100 multiple choice questions and 5 open response questions scored with partial credit, you can calibrate all items easily onto a common scale. Because no programming code is involved (point-and-click only), even researchers new to IRT can easily produce such powerful analyses.

Using Xcalibre 4

Xcalibre 4 is designed to be user-friendly, with a straightforward graphical user interface that involves no DOS-style command code. All options are specified by radio buttons and check boxes; once you have all of your specifications set, simply hit the "Run" button!