OBJECTIVE: This study examined the construct validity of the In-Hand 
Manipulation Test (IMT) by assessing the test's ability to discriminate between 
samples of children with and without known fine motor problems.
METHOD: The IMT was administered to 55 children without known fine motor 
problems and 24 children with spastic diplegia who had mild to moderate fine 
motor problems. Construct validity was estimated by evaluating how accurately 
the IMT classified the children as having or not having fine motor problems on 
the basis of total score.
RESULTS: A discriminant analysis indicated that IMT total score correctly 
classified 83.33% of the participants as having or not having fine motor 
problems.
CONCLUSION: The IMT has adequate construct validity to classify the participants 
of this study and for continued use as a research instrument to assess 
children's in-hand manipulation skills. Additional validity studies of the IMT 
are needed with other samples of children before its use for clinical purposes.