The Kidtalk Interactive Diagnostic Test of Aptitude for Language Knowledge (KIDTALK) is an assessment instrument designed for identifying children with specific language impairments not associated with limited English proficiency. It is based on three principles: (1) a language disorder can be identified by testing an individual's potential for acquiring linguistic features of a novel language; (2) language disorders can be distinguished from language differences by developing test items that meet two criteria (especially difficult for the language impaired while relatively easy for non-language impaired and equally challenging for groups of children with different cultural/linguistic backgrounds); and (3) language disorders can be identified efficiently and easily using computer technology. Development of the test in non-computerized form, then programming and piloting of the software with several age groups are described, revisions are chronicled, and validity results are reported. Plans for modifications are also noted. (MSE)