Assessment & Research

A brief report on a comparison of time-sampling procedures.

Thomson (1974) · Journal of applied behavior analysis 1974
★ The Verdict

Check your time-sampling plan against continuous data before you trust the numbers.

✓ Read this if BCBAs who rely on interval recording in clinics or schools.
✗ Skip if Practitioners who already record every response in real time.

01Research in Context

01

What this study did

The author lined up different time-sampling plans head-to-head. Each plan watched the same short clips of a teacher’s behavior.

Goal: see which quick, intermittent method best matched the gold standard of continuous recording.

02

What they found

Some sampling plans tracked the true picture. Others missed large chunks of behavior.

The paper warns: pick a plan, then test it. Don’t trust any pattern until you check its accuracy.

03

How this fits with other research

Skrtic et al. (1982) extends this idea into busy classrooms. They built a one-minute sheet that lets you watch 18 behaviors across several kids at once while still hitting over 90% agreement.

Field et al. (2001) pushes further. They show that real-time, moment-by-moment recording clarifies fast changes within a session—something any interval plan can blur.

Lloyd et al. (2018) echo the same tune decades later. They compared ways to measure contingency and again found event-based beats interval-based unless you tune the interval method to the schedule.

04

Why it matters

You probably can’t watch every second. Before you settle on 10-s partial, 15-s momentary, or any other quick plan, run a short accuracy check against continuous data. Five minutes of double-coding can save you from weeks of misleading graphs.

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→ Action — try this Monday

Code one session twice: once with your usual interval sheet and once continuously, then compare.

02At a glance

Intervention
not applicable
Design
other
Finding
not reported

03Original abstract

Much behavioral research has been based on an observation method in which an observer continuously time-sampled the occurrence of certain responses, typ- ically making a notation of occurrence or nonoccur- rence every 10 sec. Research and training settings often had the resources to allow such recording for every subject under study. Applied settings, by con- trast, often could not afford an observer for every subject under study, and at present, even research and training settings find their funding inadequate for continuous time-sampling. Thus, intermittent timesampling becomes necessary, and the question arises: how accurate is recording in each of the various possi- ble patterns of intermittency? This brief report uses the teacher-training model to examine some quantita- tive comparisons.

Journal of applied behavior analysis, 1974 · doi:10.1901/jaba.1974.7-623