Further evaluation of latency measures in the assessment and treatment of severe self‐injurious behavior
Latency alone can trick you into quitting a working SIB treatment—always check rate data too.
01Research in Context
What this study did
Perrin et al. (2018) tested how well latency data alone guides treatment for severe self-injury. They ran a latency-based functional analysis, then built a treatment with functional communication training. Throughout treatment they tracked both how soon the first hit occurred and how many total hits happened.
All participants were adults with intellectual disability and long histories of hard hitting or head banging. The team wanted to see if the time-to-first-hit measure would give them a clear green or red light for treatment decisions.
What they found
Latency numbers jumped around too much. A session could look like a failure because the first hit happened fast, even when the total number of hits was dropping. Relying only on latency would have made the team quit strategies that were actually working.
They ended up using a hybrid graph that plotted both latency and rate. Only when both lines moved in the same direction did the team feel confident about their next step.
How this fits with other research
Liollio et al. (2020) ran a similar head-to-head test. They also saw that latency worked better when problem behavior was frequent, while rate worked better when it was rare. Together the two studies warn: pick your metric to match the behavior's speed, not the other way around.
Imler et al. (2024) took the latency idea into preference assessments and found the same pattern: latency saved time, but for one participant the numbers were too jumpy and needed extra rules. The theme is clear—latency is fast, but sometimes too sensitive.
Bigby et al. (2009) looked at observer accuracy and showed that no single counting rule is perfect. Their message pairs with Perrin's: measure twice, with different lenses, before you trust the trend.
Why it matters
If you treat severe SIB, plot both latency and rate every session. When the two disagree, keep teaching and collecting data for one more day before you change course. This simple dual graph can stop you from abanding a good intervention too soon.
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02At a glance
03Original abstract
Recent research has demonstrated the utility of latency measures during the functional analysis of problem behavior; however, few studies have evaluated the utility of latency measures during subsequent treatment analyses. The current study seeks to extend the literature on the use of latency measures during the treatment of severe self‐injurious behavior (SIB). Following a latency‐based functional analysis, a treatment analysis was conducted using a hybrid procedure in which baseline sessions were terminated following the first instance of SIB, and test sessions ended after a fixed length of time. Latency to SIB was compared across conditions, whereas latency and rate measures for both SIB and functional communication responses were compared for the functional communication training condition. Results suggest that latency measures may be too sensitive during treatment analyses and that it is beneficial to use a hybrid procedure that allows for both latency and rate comparisons.
Behavioral Interventions, 2018 · doi:10.1002/bin.1520