Why don't click-through-rate and no-click-rate add up to 100%?

You may expect that the click-through-rate (CTR) and no-click rate in Algolia Analytics would add up to 100%. To understand why they don’t, you need to understand how Algolia computes each of these metrics.

Algolia calculates CTR based on the total number of tracked searches. These are searches where clickAnalytics is set to true, including searches with no results. The CTR is the percentage of tracked searches that generated at least one click on a result.

Algolia computes the no-click-rate based on the total number of tracked searches with at least one result. The no-click-rate is the percentage of tracked searches yielding results that have a query that never generates any clicks.

Because Algolia CTR and no-click-rate base themselves on different groups of searches, they aren’t comparable. Algolia computes CTR based on the total number of tracked searches while no-click-rate is based on tracked searches with at least one result.

The opposite of no-click-rate isn’t CTR. It’s the percentage of tracked searches with results that always generate at least one click. This isn’t a metric Algolia analytics tracks.

Imagine users on a grocery store app using Algolia searching for fruit. The grocery store owner wants to understand how each query is performing. These are the metrics they see:

Assume that all three queries, “orange”, “apple”, and “banana”, yield results.

To calculate the overall CTR for these searches, Algolia divides the number of tracked searches with at least one click by the total number of tracked searches. In this case, 25/50 = 50% overall CTR. Algolia also calculates CTR on a per-query basis and displays this information on the Analytics dashboard.

To calculate the no-click-rate, Algolia divides the number tracked searches that yielded results but never generated clicks by the total number of tracked searches. Though some searches for “orange” and “apple” don’t generate clicks, searches for these terms aren’t counted as searches without clicks because their queries sometimes generate clicks. Only the query “banana” returns results but never generates clicks, so the no-click-rate is 20/50 = 40%.

You can find more information about queries included in the no-click-rate metric in the Searches without Clicks section of the Analytics dashboard.