AI search

Four engines. Four answers.

We put 12 Australian patient questions to four AI engines on 12 September 2026 and classified all 427 citations.

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The easy part

Being named is normal.

Perplexity cited a clinic's own site in 12 of 12 answers. Claude in 11. ChatGPT in 9. Google AI Overviews in 8. Across the four, 167 distinct Australian clinic websites were cited.

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The advice everyone gives

It was not the directories.

A provider's own website took 60.3% to 71.7% of all citations. Directories, comparison sites and insurers took 6.2% to 21.3%.

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The surprise

Google leaned on directories least.

Google AI Overviews cited a directory in 6.2% of cases, the lowest of the four. Perplexity was highest at 21.3%, and still cited clinic sites three times more often.

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The hard part

74.3% were cited by one engine only.

Of the 167 clinic sites cited, 124 appeared on exactly one engine. Twenty-seven on two, ten on three, six on all four. Winning one race says almost nothing about the other three.

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And yet

Every question had a shared core.

In 11 of the 11 comparable questions, at least two engines cited the same clinic. A small core most engines agree on, wrapped in a long tail unique to each.

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Where Google said nothing

No overview on 3 of 12.

Including the most commercial question in the set, which asked for the best physiotherapist in a named Sydney suburb. On those, the ordinary blue links were the whole answer.

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The error worth knowing

It sent Hobart to Indiana.

Seven citations pointed outside Australia, all from one engine. A Hobart back-pain question returned four US practices. A Newcastle NSW sleep study returned the Newcastle upon Tyne NHS trust.

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Our own error rate

The machine got 21.2% wrong.

The automatic classifier flagged 212 domains as clinic sites. A human opened every one and moved 45. YouTube was in there. So was PubMed. Every figure above is the hand-corrected one.

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