How does Average Time Spent on Site differ fromTime Spent per Visit?

[cathyw49544988]

I try to understand the difference between those 2 metrics and I got the answer from document:

The difference is the denominator in the metric:

• Average Time Spent on Site uses the sequences that include a dimension item.
• Time Spent per Visit uses the visit count

  As a result, these metrics may yield similar results at a visit level, but will be different at a hit level.

But I still how did Average Time Spent on Site calculated. What's the sequences that include a dimension item?

Does anyone know?

Thanks

[Gigazelle · Accepted solution]

Time spent metrics basically take the timestamps between two image requests, and use them in their calculations. Bounces and the last hits of visits aren't included in these calculations, since they don't have any forward-looking timestamps to definitively state how long the hit lasted. The dimensions and metrics in workspace then take this information and place them into their proper buckets.