Did the Bridge Preserve the Space?

Mon, 07 Sep 2026 14:30:00 +0000

Part VI — Crossing Embedding Spaces

One bridge, eight verdicts

Take the linear A→B bridge from Chapter 19. Run every preservation metric on the same held-out set:

cosine preservation (mean cos to native target)      0.74
top-1 preservation (native NN stays NN)               0.61
top-10 preservation                                   0.88
Recall@1  (vs labels, translated query)               0.58   native: 0.63
Recall@10                                             0.71   native: 0.77
MRR                                                   0.64   native: 0.70
nDCG@10                                               0.75   native: 0.81
order preservation (Kendall τ on result lists)        0.66
cluster preservation (ARI vs native clustering)       0.80
hard-negative agreement                               0.41

Ten numbers, not one. A stakeholder who asked “did the translation work?” gets a table, and the table says: coarse structure preserved, fine order degraded, hard distinctions near the source encoder’s own native performance.

Cluster Preservation on Programmer.ie: Modern AI programming

Did the Bridge Preserve the Space?

One bridge, eight verdicts