To measure user engagement, you can segment users depending on how far they have scrolled down the page.
 
This segment includes users who have scrolled down at least 50% of the page.

This behaviour is captured using the PageviewEngagement event and the total.completion property:

Please note, scroll depth is calculated with 1 equal to 100%. Eg. 50% = 0.5; 75% = 0.75

Did this answer your question?