The Goodnight Screen Media Study

Inclusion Criteria: * preschool-aged children (4.0 to \<5.0 years old) and their parent * living in the Greater Houston area. * parent must be a biological parent or legal guardian who lives with the child ≥50% of the time and has a primary role of caring for the child * parent is comfortable participating in the study and responding to questionnaires in English. * The child does not have to have access to mobile device, but if they do, the primary device they use has to be an Android OS ≥5.0 either used only by the study child or shared with others, or an Apple iOS ≥14.0 that only the child uses. * Parent and child must be fluent in English. Exclusion Criteria: * The child has a chronic medical condition or takes a medication affecting sleep, or circadian rhythms (e.g., melatonin supplementation, diagnosed sleep disorder, steroid use, etc.) or a diagnosed cognitive or learning impairment affecting EF (e.g., attention deficit hyperactivity disorder). * Child with blindness or significant vision problems that impacts both screen media use and sleep.