Malaspina and Coleman gave a smell-identification test to 70 subjects with a schizophrenia-spectrum disorder—that is, 70 persons who met DSM-IV criteria for either schizophrenia or for schizoaffective disorder—and to 68 healthy controls. They found that the schizophrenia-spectrum subjects were, on the whole, considerably impaired in olfaction ability compared with the controls, although there were variations among the subjects. This finding did not surprise them since olfaction deficits have been identified previously in a number of patients with a schizophrenia-spectrum disorder. In fact, Kopala is believed to be the first scientist to report such deficits, in 1987. What Malaspina and Coleman wanted to learn, however, is whether there is any link between smelling difficulties in the schizophrenia-spectrum disorders and the possession of various positive symptoms, negative symptoms, depression, or lower intelligence often stemming from these illnesses. Thus, the researchers gave a battery of tests to their schizophrenia-spectrum subjects to determine whether they possessed such symptoms. Then they looked at the data to determine whether they could make a connection between possession of any of these symptoms and smell-identification scores.