1 *Research Scholar, Department of Management, Assam Don Bosco University. **Associate Professor, Department of Management, Assam Don Bosco University. Establishing Content Validity of Questionnaires for Evaluating Training Effectiveness A Structured Expert Review Approach Bijoy A. Sangma* and Dr. Rashmita Barua** Content validity ensures that measurement tools like questionnaires fully capture the construct they aim to evaluate. This study outlines a thorough process for establishing content validity for two research tools - the Participant Questionnaire (Trainee) and the Faculty Questionnaire (Trainer) - created to assess the outcomes of professional leadership training programs delivered by HIAL. Employing a systematic six-step approach and involving a panel of nine subject matter experts, item-level and scale-level content validity indices (I-CVI and S-CVI) were computed. The impressive CVI scores of 0.99 and process ensures that the instruments are prepared for wider usage in research and training evaluation settings. Keywords: Content Validity, Questionnaire Validation, Expert Review, CVI, Training Evaluation, Psychometric Analysis, Educational Assessment ABSTRACT INTRODUCTION validity of its instruments. Content validity is crucial among the different types of validity, especially in studies utilising researcher-created questionnaires. Content validity indicates how well the items in an instrument represent the content area of the measured construct (Kimberlin & Winterstein, 2008). Unlike construct or criterion- related validity, content validity is grounded in expert judgment and systematic assessment rather than statistical inference.