Confirmatory P-technique analyses of therapist discourse: high-versus low-quality child therapy sessions

From a sample of 35 child therapy sessions, 3 of the highest and 3 of the lowest quality sessions (HQS and LQS) were identified by independent ratings on the Loyola Child Psychotherapy Process Scales. Each of the 535 therapist-utterances in the HQS and the 372 therapist-utterances in the LQS were rated on 15 language interaction scales. Principal-components P-technique analyses were applied separately to the HQS and LQS, revealing 3 factors, Responsive Informing (RI), Initiatory Questioning (IQ), and Positive Regard (PR), that seemed to correspond across session types. Using confirmatory P-technique, a general measurement model with acceptable goodness-of-fit was determined for HQS. Two factors emerged: RI and IQ but not PR. Using a bootstrap procedure, random halves of the HQS were repeatedly sampled and compared via multigroup confirmatory factor analysis to create a reference distribution of the magnitudes of their difference chi-squares. Random resamples of HQS and LQS were then compared, resulting in a second reference distribution. Statistical tests and effect-size measures revealed replicable and large differences between sessions types.