Evaluating Multiple Intensively Collected Media Use Measures: Validity and Reliability of Momentary Assessments

Momentary assessment data collection methods can capture information about constructs that vary greatly throughout the day. The Measuring Youth Media Exposure methodology implemented multiple momentary measures of media use in addition to a time use diary (TUD), allowing evaluation of the convergent and divergent validity of these momentary assessment methodologies relative to the TUD. This article presents the reliability and validity of momentary questionnaires and momentary video recordings of media use in relation to conventional TUD using an adaptation of the multi–trait-multi-method matrix. Both momentary measures show good reliability as well as convergent and discriminant validity for assessing TV, video game, computer, and cell phone use in adolescents relative to the TUD.