Clinical researchers have long recognized the potential benefit of testing hypotheses at the symptom rather than syndrome level. For example, Persons (1986) advanced similar arguments for the importance of studying schizophrenia symptoms (hallucinations, delusions, disorganization, negative symptoms) rather than the potentially ambiguous classification of schizophrenia. Although her arguments were not based primarily on psychometric concerns, she argued that a focus on the symptom level reduces misclassification, enables researchers to study the specific phenomena of interest, and thus improves theoretical understanding of the various processes underlying the different schizophrenia symptoms.
