Possible futures all at once: time frame and time lag in short-term longitudinal media effects research on well-being

Abstract When assessing media effects, we seldom consider how they change over time. Especially with the prevalence of smartphone use as short-lived, fragmented media use, a systematic approach to temporal dimensions is crucial, particularly to understand mixed effects of smartphone use on situational well-being. We employ a multiverse approach to assess the influence of two central temporal dimensions in intensive longitudinal media effects research: Time frame and time lag. We combine mobile experience sampling (T1 = 2,859, T2 = 7,708) and log data (K1 = 71,807, K2 = 259,004) from N1 = 84 and N2 = 192 participants. Building on theorizing on time in media effects research, we propose four patterns of how short-term effects on situational well-being unfold: they may follow processes of ephemerality (fleeting effects), inertia (delayed onset), reversal (changing directions), or there are no changes over time. We discuss theoretical implications and give recommendations for future studies.