How long should the test duration for an a/b test be? | Community
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January 21, 2015
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How long should the test duration for an a/b test be?

  • January 21, 2015
  • 5 replies
  • 4746 views
I have a email going out tomo to 20K ppl with an a/b test on the subject line.

I really don't want to wait too long to send out the winner bc I want it to go out tomorrow, not another day (it's related to a launch).

How long does Marketo wait before it declares an email has not been opened? I suppose that 1 hour might not be enough?

Thus, is 1 hour enough to reach the sample size of 10%? 

Thanks!
 
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Best answer by Dory_Viscoglio
It might have changed, but I believe the minimum time for the automatic winner email program sends was 4 hours at one point. If all of your recipients are in the US then Kim's suggestion of waiting about 6 hours should be good. Otherwise, you're not necessarily going to have a very representative sample of opens, and your final send might not go at a very desirable time which could impact the overall outcome. At that point, I'd probably wait 24 hours. 

5 replies

Josh_Hill13
Level 10
January 21, 2015
I doubt 1 hour is enough. A good test would be 24-48 hours. I think marketo just waits the allotted time to declare a winner when you set it automatically. Whoever opens, opens.
Level 9
January 21, 2015
I agree with Josh, 1 hour isn't enough time. However, I know I get a lot of pushback from the team if I don't have the sends all in one day. So I usually have the test send early in the morning and give it a good 6 hours or so before the automatic winner is sent.
Dory_Viscoglio
Dory_ViscoglioAccepted solution
Level 10
January 21, 2015
It might have changed, but I believe the minimum time for the automatic winner email program sends was 4 hours at one point. If all of your recipients are in the US then Kim's suggestion of waiting about 6 hours should be good. Otherwise, you're not necessarily going to have a very representative sample of opens, and your final send might not go at a very desirable time which could impact the overall outcome. At that point, I'd probably wait 24 hours. 
January 21, 2015
Thanks everyone, helpful stuff!
January 25, 2016

Hi, so there is no possible way to declare a winner after 30 minutes?

Dory_Viscoglio
Level 10
January 25, 2016

Not if you're doing it through an email program. You can set it up manually and do it after 30 minutes, but I would advise against it. Just as food for thought, on Friday, 4 hours after an email send I saw a ~20% open rate (11am ET send). As of this morning it was 39%. Obviously this could have had some regionality associated with it, but 30 minutes won't always be very indicative of actual results.