Scale development-Part 2

Administer items to a Development Sample
sample large: 1) reduce variance; 2) increase stability of covariance matrix; 3) increase representativeness (large and range of the attribute present in the popluation; similar on other factors that may influence their understanding/interpretation of items)

Sample Diversity

Evaluate the items
Goals:
1) item has high correlation with total score (latent variable)
2) items has high intercorrelation (item-item correlation)
3) item does not exit ceilling or floor effects.

Preliminary Analysis

1) check the distribution of items
2) check the coding of items
3) examine the item correlation matrix (make sure that all items are positively associated with each other)

Item-Scale Correlations
Item Variances
Item means
Factor analysis
Coefficient Alpha