This book provides thorough background information on the necessity for researchers to use a censored-inflated growth model when dealing with floor effects data. In addition, the coding for Muthen's M-Plus software (2006) gives readers a step-by-step tool to assist them in the process in order for replicaton of the models to take place. The censored-inflated growth model is an extraordinary tool for simultaneously estimating growth in the normally disrtibuted as well as censored-inflated data samples. The result is a most parsimonious and highly accurate growth model for the two samples of examinees.