Effective and efficient measurement of the development of skill and knowledge, especially in domains of human activity that involve complex and challenging problems, is important with regard to workplace and academic performance. However, there has been little progress in the area of practical measurement and assessment, due in part to the lack of automated tools that are appropriate for assessing the acquisition and development of complex cognitive skills. In the last 2 years, an international team of researchers has developed and validated an integrated set of assessment tools called highly integrated model assessment technology and tools (HIMATT) which addresses this deficiency. HIMATT is web-based and has been shown to scale up for practical use in educational and workplace settings, unlike many of the research tools developed solely to study basic issues in human learning and performance. In this paper, we describe the functions of HIMATT and demonstrate several applications for its use. Additionally, we present two studies on the quality and usability of HIMATT. We conclude with research suggestions for the use of HIMATT and for its further development.