(In)accuracy and convergent validity of daily end-of-day and single-time self-reported estimations of smartphone use among adolescents

Abstract

Overview

Understanding the measurement inaccuracy and bias introduced by self-reports of smartphone use is essential for making meaningful inferences about smartphone use and its effects. Evidence for the self-reports of smartphone use in intensive longitudinal studies is largely missing.

Study Design and Participants

Based on both self-reported and digital trace data from 137 Czech adolescents (41% girls, Mage = 14.95 years), this study examined the accuracy, directional bias, and convergent validity of:

• Daily end-of-day reports of screen time and phone-checking
• Single-time self-reports of the same behaviors

Findings

• Considerable discrepancies were found between self-reported smartphone use and digital trace data.
• There was low between-person convergent validity for all kinds of self-reports assessed.
• Respondents generally under-reported screen time and phone-checking frequency compared to digital tracking, whether reporting daily or one-time only.
• The within-person convergent validity between daily self-reports and digital tracking was low—meaning self-reports poorly captured day-to-day fluctuations in actual use.

Conclusion

• Self-report insights into smartphone usage differed considerably from digital trace data among adolescents.
• Both personal and situational factors contribute to explaining the gap between digital trace and self-report data.