School-based intensive longitudinal studies show wide heterogeneity in sample size, study duration, and assessment frequency, with a median sample of 157 participants and average duration of about 13 days¶

Claim · All claims
Evidence · 1 study (3 entries) · review r3 · q2
Currency · newest study 2026 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q2 i? Sample sizes vary widely, with a median of 157 participants across included school-research articles. → Carina Schreiber & Michael Becker 2026 q2 i? Study duration averaged approximately 13 days (SD = 9.53), ranging from one day to nine weeks, often on non-consecutive days. → Carina Schreiber & Michael Becker 2026 (2) q2 i? Assessment frequency averaged about three times per day from a daily perspective and about 1.68 assessments per school lesson, with most lesson-focused articles assessing only once per lesson. → Carina Schreiber & Michael Becker 2026 (3)

Evidence¶

Carina Schreiber & Michael Becker 2026¶

Carina Schreiber & Michael Becker. (2026). Intensive Longitudinal Methods in School Research: A Systematic Literature Review. Educational Psychology Review. https://doi.org/10.1007/s10648-026-10203-x

q2 · i? · review · r3

Descriptive statistics across the 257 included articles show wide variation in sample size; the review reports that "the median of 157 participants offers a better representation of the usual sample size" given outliers with very large samples (maximum printed as 102,007).

"The average sample size varied widely; considering the impact of outliers with very large samples, the median of 157 participants offers a better representation of the usual sample size of intensive longitudinal studies in school research."

Carina Schreiber & Michael Becker 2026 (2)¶

Carina Schreiber & Michael Becker. (2026). Intensive Longitudinal Methods in School Research: A Systematic Literature Review. Educational Psychology Review. https://doi.org/10.1007/s10648-026-10203-x

q2 · i? · review · r?

Descriptive analysis of study duration across included articles: "participants were assessed for an average of approximately 13 days (SD = 9.53)", with a printed range from one day to nine weeks; the review notes many studies assessed participants only on non-consecutive days such as school days.

"Study duration also differed considerably; while participants were assessed for an average of approximately 13 days (SD = 9.53), study durations ranged from just one day to as long as nine weeks."

Carina Schreiber & Michael Becker 2026 (3)¶

Carina Schreiber & Michael Becker. (2026). Intensive Longitudinal Methods in School Research: A Systematic Literature Review. Educational Psychology Review. https://doi.org/10.1007/s10648-026-10203-x

q2 · i? · review · r?

Descriptive analysis of assessment frequency, reported separately for daily-perspective and lesson-focused articles. Daily-perspective articles averaged "approximately three times per day on average (SD = 2.63)"; lesson-focused articles averaged 1.68 assessments per lesson (SD = 1.23), with 64.9% assessing only once per lesson.

"From the daily perspective, participants were assessed approximately three times per day on average (SD = 2.63), but in more than a third of all eligible articles, the daily diary method was used, and participants were assessed only once per day."

Discussion¶

Related Claims¶

• School-research articles rarely justify their samples, sample sizes, or sampling designs when reporting intensive longitudinal studies — related
• Design parameters for preschool outcomes show substantial heterogeneity across populations, as reflected in wide 95% prediction intervals — related
• School research using intensive longitudinal methods predominantly focuses on students, with teachers rarely assessed and simultaneous student–teacher perspectives rare — related