Review of factor analytic studies examining symptoms of autism spectrum disorders.

Shuster et al. (2014) looked at 36 studies that used factor analysis on 13 different autism checklists.

They wanted to see if autism traits group together the same way no matter which tool you use.

Every checklist showed the same two clusters: social-communication problems and restricted-repetitive behaviors.

The two-domain pattern held across age, IQ, and language level.

Sajith et al. (2008) used a different math model and found discrete autism subgroups, not smooth dimensions.

The papers seem to clash, but one used taxometrics (looking for categories) while Jill used factor analysis (looking for dimensions).

Cholemkery et al. (2016) later blended both views: ADI-R scores form three severity-graded clusters inside the same two domains.

Morales-Hidalgo et al. (2018) stretched the idea into regular schools and showed the traits sit on a continuum even in kids without an autism label.

You can trust that any valid autism tool will give you two scores—social-communication and restricted-repetitive.

Use these domains to track progress, explain results to parents, and pick targets that line up with the evidence.