free package for analyzing data from complex samples, especially large-scale assessments, as well as non-assessment survey data. Has sophisticated stats, easy drag & drop interface, and integrated help system that explains the statistics as well as how to
Mierswa, Ingo and Wurst, Michael and Klinkenberg, Ralf and Scholz, Martin and Euler, Timm: YALE: Rapid Prototyping for Complex Data Mining Tasks, in Proceedings of the 12th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD-0