Factor structure of the Motivation Assessment Scale.
The MAS four-factor structure is solid, yet only trustworthy when self-injury tops fifteen episodes per hour.
01Research in Context
What this study did
The team ran a factor analysis on the Motivation Assessment Scale. They wanted to see if the four-factor structure held up in a new sample.
All participants had developmental delay and showed very frequent self-injury. The study checked if the MAS still sorted items into sensory, escape, attention, and tangible groups.
What they found
The four factors stayed intact. Items loaded on the same sub-scales as the original version.
This means the MAS can still help you guess why self-injury is happening, but only when the behavior occurs at least fifteen times each hour.
How this fits with other research
Moya et al. (2022) reviewed twenty-one component studies. Half found just one active piece of the treatment package. The MAS gives you the starting hypothesis, but you still need to test each part yourself.
Wang et al. (2010) used the same confirmatory method on a quality-of-life scale and also kept a four-factor model. Both papers show that careful stats can keep a tool useful across cultures and years.
Koegel et al. (1992) tried to confirm Greenspan’s social-intelligence model and failed. Their factors fell apart, while the MAS factors held. The difference: the MAS was built from direct observation items, not theory-first guesses.
Why it matters
You can keep using the MAS as a quick screener, but only for high-rate self-injury. Below fifteen responses per hour the factors get shaky. Start with the MAS, then run a brief functional analysis to be sure. This two-step plan saves time and protects your client from long trials.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Count the past hour’s self-injury; if you hit fifteen or more, give the MAS right then.
02At a glance
03Original abstract
The Motivation Assessment Scale (MAS) was developed to provide clinical information on four hypothesized functions that may control problem behaviour in persons with developmental disabilities. The original four-factor structure of the MAS was based on face validity, with the items being grouped in terms of each of the hypothesized functions. Validation of the scale was provided in terms of correlations between teacher ratings of eight children on the MAS and ranking of the controlling variables from functional analogue tests. In this study, staff in residential facilities rated 60 residents and teachers in schools rated 96 students on the MAS. The target behaviour rated for both samples was self-injury, with the institutional sample engaging in the behaviour more than 15 times an hour and the school sample, less than 15 times an hour. The results of factor analyses, with varimax rotation, provided a conceptually meaningful factor structure with the institutional sample, but not with the school sample. The 16 MAS items resolved into four factors that were conceptually related to four conditions that may maintain problem behaviour (i.e. sensory, escape, attention and tangible). The results suggested that the original MAS has a robust factor structure and may be clinically useful in predicting the controlling functions of problem behaviours, if the target behaviours occur at a rate no less than 15 responses per hour.
Journal of intellectual disability research : JIDR, 1993 · doi:10.1111/j.1365-2788.1993.tb00870.x