Engagement
Mouse movement
Also called cursor tracking.
Mouse movement is sampled cursor coordinates used to infer attention. The data is voluminous and counts as personal behaviour data in some regimes.
How it is measured
A script samples pointer position several times a second and sends a compressed path. Aggregates become move maps. Touch devices have no equivalent, so the data covers desktop only.
Tarsier does not collect cursor paths, which keeps payloads tiny and avoids a consent question.
Worked example
A retailer records cursor paths on one product page for a week. The data shows 38 percent of cursors hover over the shipping note for at least 2 seconds, which suggests people are looking for the cost.
They move the shipping cost to the top of the page, and the hover rate falls to 11 percent.
How it differs
Mouse movement logs paths. A heatmap aggregates them. Session replay plays them back. Cursor position is a weak proxy for where someone is looking.
Common errors
Treating hover as reading. Ignoring touch users. Collecting paths without consent. Overfitting to a few sessions. Storing raw paths long past their use.
In practice
Ask whether click or scroll data could answer the same question. If it can, skip movement tracking.