reliability
Assess internal-consistency reliability of scale items by calculating Cronbach's alpha, McDonald's omega, average inter-item correlation, and item-level statistics, flagging items that weaken the scale.
Instructions
Internal-consistency reliability for a set of scale items: Cronbach's alpha with its confidence interval, McDonald's omega, the average inter-item correlation, and per-item statistics including the corrected item-total correlation and alpha-if-dropped. Flags items that weaken the scale. Use reverse (with scale_max) for reverse-worded items.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| data | Yes | Dataset name in the session. | |
| items | Yes | Item columns belonging to one scale. | |
| digits | No | Decimal places. | |
| reverse | No | Items to reverse-score before analysis. | |
| scale_max | No | Highest possible response value, used for reverse scoring (e.g. 5 or 7). | |
| conf_level | No | Confidence level for alpha. |