Content
Site search
Also called internal search.
Site search is the on-site search feature whose queries you choose to record. What people type is the most direct statement of what they could not find.
How it is measured
Capture the query string when a search is submitted, along with the count of results returned. Many sites already have a ?q= or ?s= parameter, which makes the measurement a matter of reading the URL. A search with zero results is the most valuable row.
Tarsier does not collect search terms by itself. Send one custom event per search with the query in the data field, trimmed to the 500-character limit, and keep any email-like strings out.
Worked example
A hardware store's search box handles 3,300 queries in a month. 'torx bit' accounts for 190 and returns no results because the catalogue lists the item as 'star bit'. The same month 'return policy' appears 140 times.
The store adds a synonym and moves the policy into the footer. Zero-result searches fall from 22 to 9 percent.
How it differs
Site search is the feature and the data it produces. Internal search is another name for it. A query parameter is where the term usually sits in the URL. A search-engine query is typed elsewhere and tells you nothing about your own catalogue.
Common errors
Logging queries that contain personal data. Ignoring zero-result searches. Counting searches as sessions. Letting bots flood the log. Changing the parameter name without updating the tracker.
In practice
Review the top 20 queries and every zero-result query once a month. Fix the content or add a synonym for the most frequent ones first.