Integrated Knowledge Systems

Integrated Knowledge Systems provides business solutions when new perspectives are needed to break the boundaries between research and practice. IKS does this by bringing together research and theory in innovative ways, resulting in superior and revolutionary analytic and predictive tools. We have extensive experience in:


Creation and implementation of econometric modeling software and computer simulations. Applications including catastrophe models as applied to bandwagon effects, dynamic linear programming using real-time data, and simulation of complex systems and energy networks.


Automatic text analysis and extraction of meaningful topics from raw documents using latent semantic analysis (LSI/LSA) and related methods. Applications range from the pricing of web advertisements to the scoring of students' essay-style answers on scholastic achievement tests.


Online testing, and computer adaptive testing (CAT) for educational and psychological purposes, integration of multiple choice and open-ended response formats within the same CAT session. Our extensive experience covers the entire testing cycle in small-scale to state-wide testing programs with over 1M annual test takers.


In the area of crowd sourcing we have pioneered new approaches to validate workers' responses, while correcting for judgment severity/ easiness and other biases. Due to its scalability, these approaches apply to small, medium, and large-scale settings with millions of observations.


Following his undergraduate studies at the University of Groningen, the Netherlands, Rense Lange was awarded a Doctorate in Psychology and a Master's Degree in Computer Science from the University of Illinois at Urbana-Champaign, USA.

He has published over 75 refereed papers, books, and book chapters in the areas of artificial intelligence (data mining and crowd sourcing), computer science, econometrics, education, medicine, psychology, psychiatry, and psychometrics.

While teaching at the University of Illinois, Dr. Lange founded Integrated Knowledge Systems (IKS) which provides test administration, psychometrics and quality control services for medium and large scale clients, at the US state and district level, in educational assessment and personnel testing. 

Dr. Lange currently is a Research Professor at ISLA/CEIMOM in Vila Nova de Gaia - Porto (Portugal) focusing on advanced assessment systems and recommender systems.As well, he is a visiting scientist at various research centers working on crowd sourcing, teacher evaluation, item response theory, computer adaptive testing, automated essay scoring, and other natural language systems.



IKS works on project with

Rense Lange
Integrated Knowledge Systems