Prune Transformer Attention Heads with Measured Impact
A multi-head attention block can contain heads whose removal changes a target metric very little on a chosen evaluation set. That observation makes attention head pruning attractive: identify low-impact heads, remove their contribution, and retain the heads that matter more for the target workload. The difficult part is not setting a head output to zero. It is deciding what that intervention measures and whether the resulting model actually executes less work. A masked head, a structurally removed head, and a faster attention kernel are related ideas, but they are not the same result.