Sk. Hoge et al., THE MACARTHUR ADJUDICATIVE COMPETENCE STUDY - DEVELOPMENT AND VALIDATION OF A RESEARCH INSTRUMENT, Law and human behavior, 21(2), 1997, pp. 141-179
Assessment of competence to stand trial is a common evaluation that ca
n have substantial consequences for defendants and the criminal justic
e system. Despite a voluminous literature, much remains unknown. An ob
stacle to progress in understanding what is better termed ''adjudicati
ve competence'' is the absence of structured standardized research mea
sures for assessment of defendants. This article presents the legal fr
amework assessment strategy, instrument description, psychometric prop
erties, and construct validation of the MacArthur Structured Assessmen
t of the Competencies of Criminal Defendants (MacSAC-CD). The measures
meet or exceed accepted indices of internal consistency, and intersco
rer agreement. Observed patterns of correlations among measures suppor
t the underlying theoretical structure of competence-related abilities
. Moreover the MacSAC-CD distinguishes groups of competent and incompe
tent defendants; reflects changes in competence status; and correlates
positively with clinical judgments, negatively with psychopathology a
nd impaired cognitive functioning, and negligibly with cynicism toward
the justice system.