ACER ConQuest 5

Author(s) : Adams, R. J., Wu, M. L., Cloney, D., Berezner, A., and Wilson, M.R. (2020)

Publisher : ACER


In stock
In stock

ACER ConQuest 5 is a major version update to ACER ConQuest.

ACER ConQuest is a computer program for fitting both unidimensional and multidimensional item response and latent regression models. It provides data analysis based on a comprehensive and flexible range of item response models (IRM), allowing examination of the properties of performance assessments, traditional assessments and rating scales.

ACER ConQuest also offers wider measurement and research community analysis procedures based on the most up-to-date psychometric methods of multifaceted item response models, multidimensional item response models, latent regression models and drawing plausible values.

ACER ConQuest software includes the following features:

  • A choice of marginal maximum likelihood, joint maximum likelihood, or, new in Version 5, Bayesian Markov Chain Monte Carlo (MCMC) estimation
  • With MCMC estimation, the ability to add random effects to the item response model
  • Implementation of multidimensional and multifaceted Bock model and generalised partial credit model (GPCM)
  • Estimation of the Bradley–Terry–Luce (BTL) model for pairwise comparisons
  • Direct reading of SPSS data files and CSV text files
  • Output of results to SPSS, EXCEL, CSV, or other text files
  • A wide array of graphical outputs, including Wright maps, Wright predicted probability maps, likelihood plots, and information maps
  • Person fit and residuals
  • Latent variable path modelling
  • Mantel-Haenszel DIF estimates
  • Powerful manipulation of matrix variables and control logic (if, while, do) for advanced modelling including specifying custom design matrices or fitting iterative models.
  • Integration with R through the conquestr library
  • Advanced features, including the ability to impose new constraints on GPCM models, including imposing maximum and positive scores, as well as freely estimated variances through slope constraints.

ACER ConQuest 5 is initially available for download as a free 30-day trial. After downloading the trial, a licence can purchased via the ACER shop.

The following licences require approval:

  • Instructor Licence (annually per course)
  • Extended Licence (annual, extensions subject to approval)

For technical support, please email

Before you download the software you are required to read the below licence agreement.

ACER ConQuest, ACER Licence Agreement

Adams, R. J., Wu, M. L., Cloney, D., Berezner, A., and Wilson, M.R. (2020)