Collaborative problem-solving (CPS) is an essential skill in a knowledge-based economy. As the world moves towards inter-connectedness, economically and politically, CPS is one of the several defined skills that will be critical in the 21st century (Binkley et al., 2012). Developing these skills will be a mandate for 21st century education. In line with the imperative that something cannot be improved unless it can be measured, there is considerable challenge in measuring CPS skill using conventional assessment tools. This paper presents an innovative online assessment tool that is based on big data analytics to measure CPS skill for any pair of students in real-time and without language or geographic restrictions. This tool has been trialled across 6 countries and is currently presented in four languages (English, Spanish, Finnish and Dutch).