PARSCALE

Overview

The flexibility and the wealth of information provided by this program have kept it in regular use by researchers around the world. The program offers the following:

  • One, two, and three-parameter logistic models
  • Samejima’s model for graded responses
  • Master’s partial credit model
  • Generalized partial credit model
  • Analysis of rating scale items such as open-ended essay questions
  • Analysis of multiple-choice items
  • Differential item functioning (DIF)
  • Analysis of mixtures of item types
  • Rater’s-effect analysis
  • Multiple-group polytomous item response models
  • Presentation quality IRT graphics, can be imported in Word, Access, etc.

Examples

All PARSCALE examples contained in the PARSCALE guide are shown below. The complete examples, including data and syntax, are available as zip files for each example. The final item contains the entire set of PARSCALE examples.

Item calibration and examinee Bayes scoring with the rating-scale graded model (complete example zipped)

Examinee maximum likelihood scoring from existing parameters (complete example zipped)

Calibration and scoring with the generalized partial credit rating-scale model (complete example zipped)

Two-group differential item functioning analysis with the partial credit model (complete example zipped)

A test with 26 multiple-choice items and one 4-category item: 3PL logistic and generalized partial credit model (complete example zipped)

Analysis of three sets containing items with two and three categories: calculation of combined scores  (complete example zipped)

Raters-Effect model: multi-record input format with varying numbers of records per examinee (complete example zipped)

Raters-Effect model: one-record input format with same number of records per examinee (complete example zipped)

Raters-Effect model: one-record input format with varying numbers of records per examinee (complete example zipped)

all_examples (zipped)

Support

SSI, Inc. offers a technical support service via e-mail. This service is only available to registered end users of the SSI software products. Click here to view SSI’s policy and procedures for obtaining technical support.