The CogStyle scale was originally developed by Dr. Jones to facilitate equitable assessment of personality traits among persons with and without a disabling visual condition. The history of the instrument is available in a Series Two lab report (lab report 2-5); data gathered with Internet/WWW administration of the instrument are available in a Series Four (lab report 4-1) study and a Series Six (lab report 6-1) study.
The previous studies emphasized investigation of four global personality preference traits available in the scale: attitude (extraversion- introversion); approach (data-ideas); focus (things-people); and process (detailed-contextual).
The purpose of this study was to obtain reliability data for the core dimensions that are used to calculate the global scores, the Holland vocational personality traits of Realistic, Investigative, Artistic, Social, Enterprising, and Conventional.
Method
Participants
The participant sample for this study was comprised of upper division and graduate students enrolled in the fall of 2009 in educational psychology courses with a research participation requirement. A total of 105 subjects provided complete data for this study.
Instrumentation
Participants in this study completed the 30 item CogStyle scale in an online format.
Procedures
Students could choose to meet their research participation requirement through participation in one of several studies offered in the fall of 2009. In one of the studies, CogStyle was included along with several research scales assessing affective and cognitive characteristics. Students completed this study through the Experiment Management system in an online format using computers available on campus or their own resources.
Split-half reliability coefficients (odd-even) with Spearman Brown correction were calculated for each of the six Holland vocational personality trait dimensions provided in the CogStyle Scale, along with the corresponding standard error of measurement. Results are in the tables below:
| mean | s.d. | ||||
|---|---|---|---|---|---|
| Realistic | |||||
| Investigative | |||||
| Artistic | |||||
| Social | |||||
| Enterprising | |||||
| Conventional |
| R | I | A | S | E | C | ||
|---|---|---|---|---|---|---|---|
| Realistic | 1.00 | -.11 | -.24* | -.28** | -.23* | .05 | |
| Investigative | 1.00 | .04 | -.36** | -.24* | -.33** | ||
| Artistic | 1.00 | .25* | -.23* | -.27** | |||
| Social | 1.00 | -.04 | -.08 | ||||
| Enterprising | 1.00 | -.33** | |||||
| Conventional | 1.00 |
*p < .05
**p < .01
| R | I | A | S | E | C | ||
|---|---|---|---|---|---|---|---|
| Reliability | .65 | .69 | .70 | .71 | .73 | .74 | |
| SEmeas | 1.22 | 1.29 | 1.18 | 1.21 | 1.25 | 1.23 |
The internal consistency reliability coefficients (split-half) in these results appear essentially comparable to results (Lowman & Schurman, 1982) reported for the short form of Holland's Vocational Preference Inventory. Internal consistency reliability estimates equal to or higher than .50 are suggested as sufficient for group comparisons (Ware, Brook, Ross, Williams, Stewart, & Rogers, et al., 1980). Reliability estimates of .70 or higher are recommended for general use (Corcoran & Fisher, 2002; Pallant, 2007).
The results of this study appear to support reporting and use of the core Holland dimensions on the CogStyle scales. All reliability estimates exceeded the minimum for group comparisons. Reliability estimates on four of the six dimensions met or exceeded the minimum standard for general use.
The standard error of measurement (Feldt & Qualls, 1998), another indicator of scale precision, was at a satisfactory level on all dimensions.
References
Feldt, L. S. and Qualls, A. L. (1998). Approximating scale score standard error of measurement from the raw score standard error. Applied Measurement in Education, 11, 159-177.
Corcoran, K. and Fischer, J. (2000). Basic Principles of Measurement. Measures For Clinical Practice: A sourcebook. New York, NY: The Free Press.
Lohman, R.L., & Schurman, S.J. (1982). Psychometric characteristics of Vocational Preference Inventory Short Form. Educational and Psychological Measurement, 42, 601-613.
Pallant, J. (2007). SPSS survival manual. New York, NY: McGraw-Hill.
Ware, J. E., Brooke, R. H., Ross, D. A., Williams, K. N., Stewart, A. L., Rogers, W. H., et al. (1980). Conceptualization and measurement of health for adults in the Health Insurance Study. Vol I: Model of health and methodology. Doc. no. R-1987/1-HEW.
Guide to Reports