You are clustering on root words and missing the modifier that splits intent

You are clustering on root words and missing the modifier that splits intent
Grouping by the noun ignores the qualifier that changes everything. Across 1,400 modified queries:
— 'free [tool]' SERP overlap with '[tool]' ▇▇ 19%
— 'best [tool] for [niche]' overlap ▇▇▇ 34%
— '[tool] alternative' overlap ▇ 11%
— Modified terms wrongly clustered with the root ▇▇▇ 28%
Free, alternative, cheap, and enterprise each pull a different result set and a different buyer.
The mistake: a cluster keyed on the head noun that buries four distinct intents.
The fix: treat high-signal modifiers (free, alternative, vs, for, enterprise) as cluster-splitters, and confirm with SERP overlap under 30%.
Benchmark of the week: 'alternative' SERPs share only 11% of URLs with the bare brand term.