This study examined the extent to which school personnel were able to differentiate learning disabled students from low achievers by examining patterns of scores on psychometric measures. Subjects were 65 school psychologists, 38 special education teachers, and a “naive” group of 21 university students enrolled in programs unrelated to education or psychology. Provided with forms containing information on 41 test or subtest scores of 9 school-identified LD students and 9 non-LD students, judges were instructed to indicate which students they believed were learning disabled and which were non-learning disabled. Accuracy and inter-judge agreement confirmed the difficulty of differentially diagnosing students with learning disabilities suggesting that having information from a battery of tests does not increase the decision maker's ability to discriminate between LD and non-LD students. Considering the extreme difficulty of integrating empirical and non-empirical information, it is recommended that current assessment practices be simplified.