For thousands of years people from da Vinci to Einstein have created models to help them better understand patterns and processes in the world around them. Computers make it easier for novices to build and explore their own models and learn new scientific ideas in the process. This book introduces teachers and students to designing, creating, and…

This book discusses constructing variables and making measures. It begins by outlining the qualities a number must meet before it qualifies as a measure of something. The basis is the measurement philosophy of G. Rasch. The first requirement for making good measures is good raw material. To achieve the possibility of comparisons, the data must…