A simplified time-series analysis for evaluating treatment interventions.

The authors built a hand-calculation time-series test for single-case data. You only need eight points in each phase to use it.

No computer is required. The worksheet fits on one sheet of paper.

The shortcut method gives the same yes-or-no answer as longer statistics. It tells you if the intervention really changed the behavior.

Gunn et al. (2021) also give practitioners a quick tool — the COSTI form for scoring classroom moves. Both papers turn complex jobs into one-page aids.

Wynne et al. (1988) warned that many 1980s aggression studies lacked tight analysis. Knapp (1982) answered that call by giving a simple way to tighten small-N data.

Robinson et al. (2011) later said single-case designs work best when meds and behavior plans mix. W’s test fits those mixed studies because it needs so few data points.

You can run a defensible analysis without software or big samples. Keep the worksheet in your clipboard. After eight data points in baseline and eight in treatment, do the quick math and show parents or teachers clear proof the plan is working.