This book investigates the relationships between learner strategy use and performance on second language tests. To this effect, it examines the construct validity of two questionnaires, designed within a model of human information processing, that purport to measure testtakers´ self-reported cognitive and metacognitive strategy use. It then examines the construct validity of the FCE Anchor test, developed by the University of Cambridge Local Examinations Syndicate, to measure second language proficiency. This book is a useful resource for those interested in understanding the effects of strategy use on performance, for those interested in training students to use strategies in language classrooms and for those interested in using structural equation modelling as an analytic tool for examining the effects of socio-psychological background variables on performance.