Field differentiation was examined as a factor in the treatment of hospitalized patients. After measuring the differentiation of therapists and patients, three categories were established: differentiated (D), undifferentiated (U), and middle (M).
It was found that differentiation of the therapist was significantly correlated with outcome as measured by length of stay in the hospital and likelihood of substantial clinical improvement. Further, a trend was manifested toward a correlation between therapist differentiation and likelihood of readmission. In contrast the field differentiation of the patient seemed to have little impact on the outcome variables. While some tendencies were noted with regard to therapist-patient matches according to the differentiation, the numbers were too small to come to any conclusion.
The value of assigning specific therapist types to specific clinical populations where success is more likely was emphasized.
Pardes H, Papernik DS, Winston A. Field Differentiation in Inpatient Psychotherapy. Arch Gen Psychiatry. 1974;31(3):311-315. doi:10.1001/archpsyc.1974.01760150029004