Browsing by Author "Donald W. Drewes, Committee Member"

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Investigation of the Role of Pre- and Post-admission Variables in Undergraduate Institutional Persistence, using a Markov Student Flow Model
(2006-06-22) Herrera, Olga Lucia; Donald W. Drewes, Committee Member; Lynne E. Baker-Ward, Committee Member; Craig C. Brookins, Committee Member; Frank J. Smith, Committee Chair; Aaron M. Brower, Committee Member
This study used selected student record data to investigate the effect of students? characteristics prior to university admission (pre-admission variables), and academic actions and educational achievement indicators (post-admission variables) on retention in higher education. The analysis followed first-year undergraduate students at a large Midwestern university through four academic levels (freshman-senior). A Markov student-flow model was employed to estimate the probabilities of stopping out, staying at the same academic level, or advancing to a higher academic level up to graduation. Logistic regression was used to calculate fourteen transition probabilities of specific flow-model events given a profile of independent variable scores. Based on the yearly transitions, predicted probabilities of graduating after 4, 5 and 6 years were also computed. The key results are (a) The Markov student flow model and its use as a predictive tool, which allow calculation of a persistence risk value using institutional data. (b) The finding that many variables vary in predicting persistence depending on the academic level, which corroborates the need to organize the model by academic levels and indicates that it is incorrect to conclude that variables that affect persistence at one academic level do so at all levels. Relevant to the specific institution studied are the findings that variables such as Age at Entrance, and Pell Grant Indicator consistently predict lower probabilities of progressing towards graduation for all academic levels, holding other variables in the model constant. Cumulative GPA and Not Changing Majors also predict higher transition probabilities, with the strongest effect at the sophomore level. Target Minority, ACT score and High School Percentile predict higher probabilities of persisting at the Freshman level, but the effect becomes negative at the Senior level. If tested and implemented in an institution, the proposed simulation tool would allow decision-makers to examine potential effects of policies by altering variable profiles and analyzing the predicted changes in the institutional persistence of students. The probabilities obtained can be interpreted as an empirical persistence risk value.
Systematic Sources of Variance in Supervisory Job Performance Ratings: A Multilevel Analysis of Between-Rater and Between-Context Variance
(2006-12-08) Ellington, James Kemp; Lori F. Thompson, Committee Member; Adam W. Meade, Committee Member; Donald W. Drewes, Committee Member; Mark A. Wilson, Committee Chair
The appraisal of job performance is critical for both the practice of human resource management and organizational research. Furthermore, the most frequently used method for measuring performance is a supervisory rating. Given the prevalence of this method, it is crucial to understand the factors which influence rater behaviors. Recent research has indicated that a large portion of the variance in ratings is idiosyncratic to the rater (Scullen, Mount, & Goff, 2000). However, the nature of this idiosyncratic variance remains unclear. Previous models of appraisal have focused on either the cognitive processes involved, or more recently, the appraisal context. Although this recent focus on contextual issues has shown promise, the extent to which raters are influenced by the context in which they work is unknown. Therefore, the purpose of this research was to contribute to our understanding of supervisory ratings by incorporating a multilevel analytic approach in order to partition the variance between raters from the variance between contexts. This approach allowed for the investigation of several rater and context-level characteristics, in attempt to explain the variance associated with these two sources. More specifically, a conceptual model was proposed in order to examine rater-level variables including rater tendencies for leniency and halo, along with rater opportunities to observe performance. Contextual factors proposed for study included norms for leniency and halo, opportunities to observe performance at the context-level, and the nature of work/activity itself within various contexts. Moreover, this research incorporated a multidimensional performance criterion, in order to provide a more thorough investigation of the relationships of interest here. Results suggested that the rating context accounted for significant variance in both task and citizenship performance ratings. Furthermore, the rater tendency for leniency explained significant between-rater variation in both criteria. The rater tendency for halo was also significant, however this finding did not recur when analyzing a replication sample of data. At the context-level, the norm for leniency consistently predicted variance in citizenship performance, but was only a significant predictor of task performance in one sample. Finally, although these relationships were not consistent across samples, the nature of work/activity and the contextual norm for halo explained significant between-context variation in citizenship performance ratings. The interpretation and implications of these results are discussed, along with limitations of this research and suggestions for future research.