When hovering over a player, select analytics. This goes to the Player Analytics page, from which the data can be exported for the player. This will result in a spreadsheet with Views, Devices, Attention Span, Embeds and so on. This article will be specifically referring to the Attention Span data exported. Using the data found in the attention span report, you can track viewers' engagement with the video and specifically pinpoint where users begin to drop off, thereby identifying the area of the video where viewers become disinterested in the video. This data can be crucial to truly understand whether or not the delivered content is actually getting its message across and if not, the data can show exactly which parts need improvement.
On the right of the image above, is the attention span section of the exported data. This example is created with a 3 second video and a total of 2 views. When the video starts ( row 6, 0 seconds) engagement is at 100% and the amount of viewers at this time is 2 indicating that both viewers are watching/engaged at this time. The data does not change in row 7 after 1 second has passed as both viewers are still watching the video which results in 100% engagement. Then in row 8, engagement percentage has dropped to 50% and viewers have dropped to 1, indicating that one viewer (50% of the total 2 views) stopped watching the video at this point. The total length of the video ends at 3 seconds (row 9), which is where the percentage and viewers drop to zero.
This data is also visually available underneath the Combined Viewers section found in the bottom half of the same page as the player's analytics. On the left of the image above, you can see that by the 2-second mark, engagement has dropped to 50% which corresponds to the data found in the exported spreadsheet.