Time-based lag sequential analysis and the functional assessment of challenging behaviour.

Cryan et al. (1996) wrote a how-to guide. They showed BCBAs a new way to read FA data.

The tool is called time-based lag sequential analysis. It looks at what happens second-by-second.

The paper gives step-by-step math and example graphs. No new experiment was run.

The authors did not test kids or report outcomes. They only explained the method.

They showed that tiny time lags can reveal hidden patterns. A scream may follow a demand after two seconds, not right away.

Duker et al. (1991) said we need sharper FA tools. Cryan et al. (1996) answered with the lag-sequential recipe.

Kleinert et al. (2007) later reviewed the tool and called it useful in clinics. The 1996 paper became a building block.

Perez et al. (2015) ran 20 cases and proved that phased FAs give clear functions. Their micro-pattern goal matches the 1996 time lens, but they used shorter trials instead of second-by-second math.

Next time your FA data look muddy, zoom in on time. Plot what happens one, two, and three seconds after each antecedent. You may spot a delay that explains the function and saves you extra sessions.