Aiken’s V calculator
Content validity from expert judge agreement, item by item.
Calculator inputs
Results
Enter your values and press “Calculate” to see the result.
In short
- What it calculates
- Content validity from expert judge agreement, item by item.
- Formula used
V = Σ(sᵢ) / (n × c)- Example
- 4 items rated by 3 judges on a 1 to 5 scale:
Aiken’s V calculator
Aiken's V quantifies how far a panel of experts agrees on the relevance or clarity of each item in an instrument.
It is the usual way to justify content validity in a thesis.
How it works
For each item the judges' scores minus the scale minimum are summed and divided by the maximum theoretically possible. The result ranges from 0 to 1.
Formula
V = Σ(sᵢ) / (n × c)
sᵢ = rating − scale minimum
n = number of judges
c = scale maximum − scale minimum
V ≥ 0.80 is considered acceptable
Worked example
4 items rated by 3 judges on a 1 to 5 scale:
Item 1: (3+4+3)/(3×4) = 0.833
Item 4: (4+4+4)/(3×4) = 1.000
Overall V: 0.875 → adequate content validity
Explanation
It measures expert agreement, not item quality
Aiken's V quantifies how far a panel of judges agree that an item is relevant or clear. A high value means consensus, not that the item works well in practice. Content validity is only the first filter: afterwards the instrument still has to be tested with the real population.
How many judges are needed
With three or four the confidence interval is so wide that almost any result is compatible with chance. Five or more is the norm in the literature, and from eight upwards the estimate stabilises considerably. More important than the number is that they are genuine experts in the domain assessed.
What to do with a low value
It does not always mean removal. A low value can stem from ambiguous wording that confuses the judges, from the item measuring a different dimension than assumed, or from unclear instructions given to the experts. Before discarding, read their qualitative comments.
The usual threshold
0.80 is generally cited as the minimum acceptable value, and some authors accept 0.70 in exploratory phases. As with any threshold, report the confidence interval too and not just the point estimate.
Frequently asked questions
How many judges do I need?
Between 3 and 10 is standard. Fewer than 3 leaves the judgement too exposed to a single opinion.
What do I do with a low-V item?
Rewrite or drop it. The per-item table exists precisely to spot which ones need attention.
How many judges are enough?
Five or more is standard, and from eight upwards the estimate stabilises. With three or four the confidence interval is too wide.
What do I do with a low-V item?
Before removing it, check whether the wording is ambiguous or the instructions to judges were unclear. Their qualitative comments usually explain the disagreement.
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