The purpose of this quantitative, quasi-experimental study was to examine the effects of a standardized case conceptualization training workshop on 104 psychotherapy practitioners recruited from the community. A secondary purpose was to examine the relationship between participants’ attitudes about evidence-based practice and the effects of the training. Participants attended two 3-hour training workshops, which taught the integrative case conceptualization model developed by Sperry (2010b). Pre- and postintervention case conceptualization skills were assessed using the Case Conceptualization Evaluation Form (CCEF) 2.0, an updated version of the instrument used in previous studies. Additionally, participants’ views about case conceptualization were assessed before and after training using the Views about Case Conceptualization (VACC) instrument. Participants’ attitudes about evidence-based practice were also examined as a possible mediating variable between training and effect. These attitudes were assessed using the Evidence-Based Practice Attitudes Scale (EBPAS). Workshops were separated by four weeks in order to assess whether initial training effects persisted over time. Change in case conceptualization skill was analyzed using repeated measures ANOVA. Participants’ mean CCEF 2.0 scores significantly increased (p < .001) from pre-test (M = 11.9; SD = 7.74) to post-test (M = 36.7; SD = 7.80) following the first workshop. The second workshop took place four weeks later with 74 of the original 104 participants. It built on the content of the first workshop and introduced advanced concepts such as client culture, strengths and protective factors, and predictive ability. Participants’ mean CCEF 2.0 scores also significantly increased (p < .001) from pre-test (M = 35.1; SD = 8.11) to post-test (M = 66.3; SD = 10.95) following the second workshop. There was a small but statistically significant (p < .005) decrease of 1.5 points in mean scores from the end of Workshop I to Workshop II, indicating that the effects of the training deteriorate slowly over time. Participants’ attitudes about evidence based practice and some demographic variables were significantly related to training effects. Stepwise hierarchical regression analysis determined that these individual variables account for various portions of the variance in CCEF 2.0 scores. This study’s theoretical, practice, and research implications are discussed in detail. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection