In an attempt to restore the symmetry and balance between the study of person and item variation, this paper presents a novel methodology construct specification equations, which allows one to ascertain from the lawful behavior of items what an instrument is measuring. (Author/PN)

A meta-analysis was performed on the 133 cognitive and behavioral papers in autism using comparison groups in the 1999-2002 period. High-functioning (average IQ: 84.7), adolescents (average, 14.4 years) are largely dominant. IQ is the most frequent matching variable in use (51.2%). The instruments that are most frequently used to determine IQ or…