S-CVI/Ave (Scale-level Content Validity Index/Average) is the most reliable and widely recommended measure of scale-level content validity in modern research. It represents the average of all item-level I-CVI values across an entire scale or instrument. This metric has become the gold standard in scale development because it combines the benefits of item-level analysis with a comprehensive scale summary.
S-CVI/Ave is used in:
- Nursing and healthcare scale development
- Educational assessment instrument validation
- Psychological and behavioral measurement tools
- Organizational and management research
- Any field requiring expert-based instrument validation
S-CVI/Ave Formula
S-CVI/Ave = Sum of all I-CVI values / Number of items
How to Calculate
Step 1: Calculate I-CVI for each item (using the I-CVI formula: experts rating as essential / total experts)
Step 2: Add all I-CVI values together
Step 3: Divide by the total number of items
Example
A 5-item scale with these I-CVI values (5 experts rated each item):
Item 1: I-CVI = 1.0 (5/5 experts agreed)
Item 2: I-CVI = 0.8 (4/5 experts agreed)
Item 3: I-CVI = 0.8 (4/5 experts agreed)
Item 4: I-CVI = 1.0 (5/5 experts agreed)
Item 5: I-CVI = 0.6 (3/5 experts agreed)
S-CVI/Ave = (1.0 + 0.8 + 0.8 + 1.0 + 0.6) / 5 = 4.2 / 5 = 0.84
Validity Threshold
S-CVI/Ave ≥ 0.90: Excellent content validity ✓
Scale is ready for use. Proceed to reliability testing and empirical validation.
S-CVI/Ave 0.80–0.89: Acceptable validity (some revision recommended)
Items with lower I-CVI should be revised or removed.
S-CVI/Ave < 0.80: Insufficient validity
Scale requires substantial revision. Conduct another expert review after making changes.
Why S-CVI/Ave is Preferred
- Captures precision: Uses I-CVI values which are easier to interpret than CVR
- Industry standard: Most widely cited in published research (especially nursing, education, psychology)
- Clear threshold: Simple, round number (0.90) that's easy to communicate
- Recommended by experts: Endorsed by Waltz, Strickland, Lenz, Polit, and Beck
- Balances rigor and practicality: More stringent than CVI but achievable with good items
- Item-level visibility: You can see which items contributed to the overall score
S-CVI/Ave vs Other Metrics
| Metric | What It Measures | Threshold | Use Case | Status |
|---|---|---|---|---|
| CVR | Item-level (individual items) | Varies by N | Initial screening | Legacy |
| I-CVI | Item-level (individual items) | 0.78-1.0 | Detailed item review | Current |
| CVI | Scale-level (average of CVR) | 0.78-1.0 | Quick summary | Legacy |
| S-CVI/Ave | Scale-level (average of I-CVI) | ≥ 0.90 | Primary validity score | Current standard |
| S-CVI/UA | Scale-level (unanimous agreement) | ≥ 0.80 | Stringent standard | Supplementary |
Practical Guidance
If S-CVI/Ave = 0.95
✓ Excellent! Your scale has outstanding content validity. Proceed directly to pilot testing and reliability analysis.
If S-CVI/Ave = 0.88
⚠ Good, but could be better. Review items with I-CVI < 0.80, consider revising them, and optionally conduct another expert review round.
If S-CVI/Ave = 0.75
✗ Needs work. Remove or substantially revise items with I-CVI < 0.70, then conduct another expert panel review before proceeding.
Reporting S-CVI/Ave
How to report in your research paper:
"The S-CVI/Ave was 0.92, indicating excellent content validity. Of the 20 items, 18 achieved an I-CVI of 0.78 or higher, while 2 items were revised based on expert feedback and excluded."
Combining S-CVI/Ave with S-CVI/UA
Best practice is to report both metrics:
- S-CVI/Ave ≥ 0.90: Shows strong average agreement
- S-CVI/UA ≥ 0.80: Shows most items had unanimous expert agreement
Interpretation: An S-CVI/Ave of 0.92 and S-CVI/UA of 0.85 means experts largely agreed items were essential, and 85% of items had perfect expert consensus.
References
Waltz, C. F., Strickland, O. L., & Lenz, E. R. (2005). Measurement in nursing and health research (3rd ed.). Springer Publishing Company.
Polit, D. F., & Beck, C. T. (2006). The content validity index: Are you sure you know what's being reported? Research in Nursing & Health, 29(5), 489-497.
Shi, J., Mo, X., & Sun, Z. (2012). Content validity index in scale development. Zhong Nan Da Xue Xue Bao Yi Xue Ban, 37(2), 152-155.