This book deals with seven validation studies in language testing in which the author has made a contribution either solely or in conjunction with other colleagues. All the studies here are related to test validation in language testing. All the studies mentioned here have been published in different journals except one. Although the studies deal with language testing in an Iranian context, the global implications are legitimate. Almost all the studies deal with the same data set. But the studies use different approaches. At the beginning of each study it is mentioned where the study has been published.The book is a reliable source for validation researchers especially those who are interested in validating high stakes tests. The same approaches used here can be adopted for other contexts.