A. NCA is a loss.
— Yann LeCun (@ylecun) November 4, 2020
B. Siamese net is an architecture.
C. Contrastive learning is a general training paradigm to give good scores to observed things and bad scores to unobserved things.
Those are independent concepts.
You can have:
- C without A or B
- B without A or C (BYOL)