How this calculation works
Estimate the loss of independent information from positively correlated observations in equal-sized clusters.
Design effect = 1+(m−1)ρ and effective n=n/design effectA worked example
Cluster size 10 and correlation 0.1 give design effect 1.9 and effective n about 157.9.
Good to know
Use equal clusters. The result is an approximation for planning.
Reference: OpenStax Introductory Statistics (opens in a new tab) ↗
Read the result
Estimate the loss of independent information from positively correlated observations in equal-sized clusters.
The primary result is labeled “Effective sample size”. Keep the input definitions in view when comparing this result with another method.
Try a related calculation
Use equal clusters. The result is an approximation for planning.
For a related exercise, try the statistics calculator.
A few questions, answered
How can I check the default inputs by hand?
Cluster size 10 and correlation 0.1 give design effect 1.9 and effective n about 157.9.
Which rule does this calculator apply?
Design effect = 1+(m−1)ρ and effective n=n/design effect