How do you evaluate the quality of a self-supervised representation?
mediumAnswer
- (1) Linear probing: freeze encoder, train linear classifier on downstream labels → measures 'linearly separable info'.
- (2) Fine-tuning: unfreeze, full downstream training → measures 'total info'.
- (3) k-NN classification in embedding space → non-parametric.
- (4) Transfer to many tasks (VTAB, ELEVATER).
- (5) Robustness under distribution shift.
- Rule: report linear probe + k-NN + fine-tune; don't over-index on one downstream task.
Check yourself — multiple choice
- Just accuracy
- Linear probe (linearly-separable info) + fine-tune (total info) + k-NN (non-parametric) + transfer to VTAB / ELEVATER + robustness; report multiple, not one task
- Random
- Only silhouette
SSL evaluation: linear probe + k-NN + fine-tune + transfer benchmarks.
#representation-learning#evaluation
Practise Unsupervised Learning
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