Intermediate Effects in Psychodiagnostic Classification

Abstract

Most comparative studies of performance in psychodiagnostic classification contrast novices with very experienced clinicians, and do not include a group with an intermediate level of experience. We describe an empirical study involving 41 clinicians with three levels of experience. We asked novices, intermediates, and very experienced psychodiagnosticians to give the diagnostic (DSM) classification for 10 written cases. We found an intermediate effect in diagnosticians' decision time and correctness: Intermediates performed worse and faster than both novices and very experienced clinicians. In line with most other studies, we found that experienced diagnosticians were not significantly more accurate than novices.

Experts and Decision Making: First Steps towards a Unifying Theory of Decision Making in Novices, Intermediates and Experts

“…Results showed that the application of biomedical knowledge in the course of expertise development first increases and later decreases again. That is, in contrast to Witteman and van der Bercken (2007), an inverted U-shaped function was found. Moreover, the authors were able to demonstrate that this decrease from intermediate to expert level was not due to decay or inertia but to the encapsulation of biomedical knowledge in clinical knowledge.…”

“…One puzzling problem seems to appear at an intermediate level of expertise. In studies contrasting novices, persons at an intermediate level of expertise, and experts, some researchers find a decrease in performance on a medium level; that is, intermediates perform worse than experts and novices (e.g., Patel, Evans, & Groen, 1989;Witteman & van der Bercken, 2007), whereas others show intermediates doing better than novices and experts (e.g., Schmidt & Boshuizen, 1993) (for a discussion of these divergent results on the so-called 'intermediate effect', see, for example, Williams & Noyes, 2007). To consider reasons for these differences in terms of PCS models we will first sketch three of the respective studies.…”

“…Sonnentag, 2000). Moreover, theories on the development of expertise vary greatly in their assumptions: there are theories proposing a discontinuity in the development of expertise (so-called intermediate effect, i.e., a decrease in performance on a medium level of experience, e.g., Patel, Arocha, & Zhang, 2005;Witteman & van der Bercken, 2007); theories that expect a performance plateau in the development of expertise that people can only overcome with deliberate effort (deliberate practice by Ericsson, Krampe, & Tesch-Römer, 1993); and theories that assume a more or less continuous development of expertise (e.g., Dreyfus & Dreyfus, 1986), sometimes with qualitative leaps (e.g., Benner, 1984).…”

Deliberative versus Intuitive Psychodiagnostic Decision

“…Witteman & Van den Bercken, 2007) vignettes were used to optimize methodological rigor (cf. Bachmann et al, 2008); this greater methodological rigor, however, comes at the cost of the ability to generalize our results to more realistic diagnostic situations.…”

“…While it is self-evident that clinical psychologists who have worked longer in the field gain more experience, it has also been shown that they do not necessarily gain more expertise in psychodiagnostic decision-making (Spengler et al, 2009;Vollmer et al, 2013): Even after years of experience, clinical psychologists are relatively poor at categorizing mental disorders into DSM categories (Brailey et al, 2001;Schulte-Mecklenbeck et al, 2015) and make judgments strikingly similar to those of novices (e.g., AEgisdóttir et al, 2006;Garb, 1998;Strasser & Gruber, 2004;Witteman & Van den Bercken, 2007).…”