ConQuest is a computer program developed at the Australian Council for Educational Research (ACER) for fitting item response and latent regression models. It provides a comprehensive and flexible range of item response models to analysts, allowing them to examine the properties of performance assessments, traditional assessments and rating scales. ConQuest also makes available, to the wider measurement and research community, the most up to date psychometric methods of multifaceted item response models, multidimensional item response models, latent regression models and drawing plausible values.