Participants and instrument

• N: 1,225 teenagers (ages 13–19)
• Recruitment: Social media + paid ads
• Measures: Sleep position at sleep/wake, dream qualities (happiness, scariness, vividity, bizarreness, romance), habits (screen time, sleep length), demographics

Preprocessing

• Parsed ranges (e.g., 6–8 hours) to midpoints
• Excluded blanks and zeros for averages
• Grouped wake positions into body orientations

Position grouping

Wake positions mapped to categories based on our analysis code:

• Back: 1, 4, 5, 12, 13, 14, 16, 20, 22
• Left: 3, 6, 11, 21
• Right: 9, 18, 19, 23
• Stomach: 2, 7, 8, 10, 15, 17, 24

Limitations

• Self-report bias; variability in interpretation of questions
• Correlation does not imply causation
• Potential confounders (screen time, sleep length) not fully controlled