Design Effect Calculator
Calculate the design effect (DEFF) for cluster sampling and complex survey designs to determine effective sample size.
Calculation Method
Typical ICC Values:
Design Effect (DEFF)
1.9500
Moderate loss of efficiency
Sample Size Inflation
1.95x
Cluster Size
20
ICC
0.05
Interpretation:
To achieve the same precision as a simple random sample, you need approximately 1.9500 times as many observations.
What is Design Effect?
The design effect (DEFF) measures the loss in efficiency from using a complex sampling design instead of simple random sampling. A DEFF greater than 1 indicates the complex design requires more observations to achieve the same precision. It is commonly used in cluster sampling, stratified sampling, and multi-stage designs.
Formula for Cluster Sampling
DEFF = 1 + (m - 1) × ICC
Where m is the average cluster size and ICC is the intraclass correlation coefficient.