psychometric (version 2.4)

CVratio: Content Validity Ratio

Description

Computes Lawshe's CVR for determining whether items are essential or not.

Usage

CVratio(NTOTAL, NESSENTIAL)

Value

Content Validity Ratio

Arguments

NTOTAL

Total number of Experts

NESSENTIAL

Number of Experts indicating item 'essential'

Author

Thomas D. Fletcher

Details

To determine content validity (in relation to job performance), a panel of subject matter experts will examine a set of items indicating whether the items are essential, useful, not necessary. The CVR is calculated to indicate whether the item is pertinent to the content validity.

CVR values range +1 to -1. Values closer to +1 indicated experts are in aggreement that the item is essential to content validity.

References

Lawshe, C. H. (1975). A quantitative approach to content validity. Personnel Psychology, 28, 563-575.

Examples

# Using 5 Expert panelists (SMEs)
# The ratings for an item is as follows:
# Rater1 = Essential
# Rater2 = Essential
# Rater3 = Essential
# Rater4 = Useful
# Rater5 = Not necessary
# # essential = 3
CVratio (5, 3)