Artificial data created by Willett (1988) measuring changes in performance on a hypothetical "opposites naming" task over a four week period in a sample of 35 people.
Format
A person-period data frame with 140 rows and 5 columns:
- id
- Participant ID. 
- wave
- Wave of measurement. 
- time
- Wave of measurement centred at time 0. 
- opposites_naming_score
- Score on the "opposites naming" task. 
- baseline_cognitive_score
- Baseline score on a standardized instrument assessing general cognitive skill. 
Source
Willett, J. B. (1988). Questions and answers in the measurement of change. In E. Rothkopf (Ed.), Review of research in education (1988–89) (pp. 345–422). Washington, DC: American Educational Research Association. https://doi.org/10.3102/0091732X015001345