Conversion
Abandonment rate
Also called drop rate.
Abandonment rate is the share of started processes that do not finish. It is a generic ratio that shows up in carts, forms, signups and bookings.
How it is measured
Pick the start and the finish, count each over the same dates, and divide the gap by the starts. Starts are the denominator: people who never began are not abandoners. If the process spans days, decide whether late finishers count.
In Tarsier you create the two numbers as events, one at the start and one at completion, and read them side by side. The ratio is yours to compute and name.
Worked example
A ferry operator's booking flow logs 2,600 started bookings in August and 1,090 confirmed ones. That is 58 percent abandonment. But 380 of the abandoned starts were people checking whether a vehicle fits, who never planned to book that day.
The operator adds a vehicle-size calculator outside the flow. Starts fall to 2,200 and abandonment to 50 percent, with the same 1,090 bookings.
How it differs
Abandonment rate is the generic ratio. Cart abandonment is the shop version with carts as the denominator. Form abandonment uses form starts. Funnel drop-off looks at one step rather than the whole path.
Common errors
Counting people who never started. Mixing start definitions between months. Treating an abandoned start as lost revenue. Ignoring resumes by email. Comparing a form to a cart.
In practice
Write the start and the finish events in one sentence, then trend the rate for at least four weeks before acting.