The motivation of stereotypic and repetitive behavior: examination of construct validity of the motivation assessment scale.
The MAS is not one-dimensional—score sensory motivation on its own before you write a behavior plan.
01Research in Context
What this study did
The team ran a Rasch analysis on the Motivation Assessment Scale (MAS). They wanted to see if the four sub-scales truly hang together.
Kids with autism or ID were rated by staff; no new data were collected, the authors re-examined existing MAS protocols.
What they found
The MAS did not act as one clean ruler. Sensory items stood apart from social, tangible, and escape items.
In plain words: treat "sensory" as its own reason for stereotypy instead of lumping it with the other three functions.
How this fits with other research
Adams et al. (2022) later saw the same flaw in the School Refusal Assessment Scale-Revised. Their autistic sample also broke the four-factor plan, a clear conceptual replication.
Pandolfi et al. (2010) found a similar mess in the GARS-2: the published sub-scales collapsed under factor analysis. Together these papers warn that autism checklists often promise neat boxes that do not exist.
Lecavalier et al. (2004) offers a rare counter-example: the NCBRF kept its factor structure in youth with ASD. The difference shows that some scales can hold up, so test each one rather than trust the manual.
Why it matters
When you give the MAS, score sensory items separately. If sensory motivation is high, plan sensory-based interventions first instead of purely social or escape plans. This small shift can save you from picking the wrong function and chasing the wrong fix.
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Pull your last five MAS protocols, re-check sensory item totals, and see if any high scores were masked by averaging across sub-scales.
02At a glance
03Original abstract
Construct validity of the Motivation Assessment Scale (MAS) (Durand, Crimmins, The Motivation Assessment Scale 1988) was studied using Rasch analysis data from 67 children (246 MASs), with dual diagnosis of autism and intellectual disability or with intellectual disability only. Results failed to support the proposed unidimensional construct or the original 4-factor structure. Some motivators appear to form a unidimensional construct: "to gain attention", "to gain a tangible object", and "to escape". There was evidence that sensory stimulation represents a different construct. Children with intellectual disability were more apt to be motivated by desire to gain a tangible item or attention. Children with the dual diagnoses were more apt to have sensory stimulation or escape from task demand as a motivator for stereotypic and repetitive behavior.
Journal of autism and developmental disorders, 2008 · doi:10.1007/s10803-007-0523-9