This research represents the second step in a planned series of studies that is expected to culminate in a behavioral measure that assesses solely for problems in thinking and perception based on the Rorschach Performance Assessment System (R-PAS; Meyer, Viglione, Mihura, Erard, & Erdberg, 2011). The Thought and Perception Assessment System (TPAS) is designed for use in clinical practice and research using all ten of the traditional Rorschach cards. Because coding only focuses on two sets of variables, test administration procedures are substantially simplified relative to the standard R-PAS procedures. TPAS will yield time savings and dimensional behavioral assessment data for the identification of problems in thinking and perception. TPAS can be further abbreviated and simplified by using it with a smaller subset of cards. These short-form card sets yield further time savings and also provide the ability to conduct alternate forms-retest evaluations with independent stimuli. Using archival data, Eblin and colleagues (Eblin, 2012; Eblin, Meyer, Mihura, & Viglione, 2014) derived the short-form card sets using only the R-PAS Thinking and Perception variables. In addition to the standard 10-card option, one short-form series consisted of two 5-card options, another consisted of two 4-card options, and the final series consisted of three 3-card options. Eblin and colleagues’ analyses demonstrated that each of the short-form card series had merit, with the 4-card series being less optimal than the 5- and 3-card series because it offers no benefit over five cards and not as many options as the 3-card series. As such, the 4-card series is not used here. In general, part-whole correlations, reliability coefficients, and validity coefficients were acceptable for each short-form card set and slightly decreased as a function of decreasing the number of cards in each series. The primary limitation of Eblin and colleagues’ (Eblin, 2012; Eblin et al., 2014) previous research is that it made use of archival data, so it was not possible to evaluate the validity of the new TPAS administration guidelines. This study addresses this limitation by collecting validity data for TPAS using the standard 10-card series and the Positive and Negative Syndrome Scale (PANSS; Kay, Fiszbein, & Opler, 1987) as a validity criterion measure. In general, TPAS interrater reliability coefficients and R-PAS to TPAS alternative forms retest correlations were acceptable, with the largest coefficients for the Thinking variables. The analyses demonstrated the validity of the Perception variables, as well as the incremental validity of TPAS over self-reported psychotic symptoms. Although the Thinking variables initially did not have a meaningful relationship with clinician ratings of psychotic symptoms using items from the Positive and Negative Syndromes Scale (PANSS), a series of supplemental analyses help to understand this anomalous finding. Specifically, the Weighted Sum of the 6 Cognitive Codes validly discriminated patients from nonpatients (M d = .87, M r = .40) and the validity with PANSS ratings of psychotic symptoms was partially obscured in the present analyses by lengthy and verbose protocols. Although not the focus of the present research, preliminary psychometric data are also provided for short-forms extracted from TPAS administrations. Implications and future directions for TPAS research are discussed.