How does BIC choose k in GMM?
mediumAnswer
- BIC = -2 log L + p log n where p = number of free parameters, n = dataset size.
- Lower is better.
- Balances fit (log L) against complexity (p log n).
- For GMM, p grows with k and covariance type.
- Standard practice: fit GMM at k = 1.., plot BIC vs k, pick the minimum (or the elbow).
- More reliable than AIC for clustering.
Check yourself — multiple choice
- Higher BIC is better
- BIC = -2 log L + p log n; fit at k=1.., pick minimum; balances fit vs complexity → standard for GMM k selection
- Same as elbow
- Random
BIC in GMM: minimize -2 log L + p log n over k.
#clustering#density#evaluation
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