Scale Overview
The Duttweiler Internal Control Index – ICI was developed by P. C. Duttweiler (1984). It is designed to measure Locus of Control. The scale is intended for use with Adults.
Scale Structure
This instrument consists of 28 items.
Response Format
Respondents rate each item using a custom response format.
Response anchors: 1 = Rarely (less than 10% of the time), 2 = Occasionally (about 30% of the time), 3 = Sometimes (about half of the time), 4 = Frequently (about 70% of the time), 5 = Usually (more than 90% of the time).
The scale includes 14 reverse-scored items to reduce acquiescence bias.
Scoring
Items are summed to produce a total score.
Total scores range from 28 to 140. Interpretation guidelines:
- Low Internal Locus of Control (External Locus of Control): 28 – 84
- Moderate Internal Locus of Control: 85 – 112
- High Internal Locus of Control: 113 – 140
Psychometric Properties
Internal Consistency: The scale has demonstrated good to excellent internal consistency with reported Cronbach’s alpha values of 0.84 – 0.85.
Administration
The scale is self-administered and typically takes approximately 8 minutes to complete. It can be administered individually or in group settings. No special training is required for administration.