Case Study Report: Post Duplication in Feed
A little while ago I had a post about spelling mistakes being a bloggers worst nightmare and was then challenged by Ms. Danielle to find spelling errors on her website. After looking through about 50 posts entirely only two very small errors were spotted and that is when she introduced the idea of post duplication. Basically what she said was that sometimes if you publish a post in Wordpress and then go back later to make some changes to it and then save the post, your feed will show two entries for the same post. In other words, your feed will show duplicate entries for the same post - one that was edited and one that was the original post. I was a little surprised by this and I knew that she was saying this from experience so, I decided to find out when the feed actually duplicates a post.
Case Study Background
To be fair, I tested several different feed readers - Bloglines, Google Reader, Rojo, Feedlounge and Newsgator. What I did was that I would go back and edit certain posts to see whether or not duplicate posts would show up in the different feed readers. I also created some posts and back dated them, what this means is that I would create a post on July 16th for example, and have the time stamp read July 10th and see how the post would be placed in comparison to the posts that were not back dated. Here are the results:
Rarely were posts duplicated
I say rarely because if you look at the approximately 132 posts that I have on the blog so far, you will notice that depending on your feed reader, you will have 2 duplicate posts. Whats surprising is that Google Reader checks my feed more frequently it seems, because both those duplicate posts show up in Google Reader and only one shows up in a few of the others. The ones that don’t show any duplicates are Bloglines and Rojo. Over the period of the case study, I posted around 28 posts and none of them were duplicated even though I must have edited some of them more than a couple times. Sometimes, I would edit them 5 times even, and they still wouldn’t show up. Either way, 2 posts out of a 132 posts is not bad considering that some changes are highly necessary and need to be made.
Why Are Some Posts Duplicated and Not Others?
Well, I dont know the answer for sure but I do have a hypothesis. What I figure is that most feed readers renew their updates every 30 minutes. So if you go back within the first couple minutes and update mistakes to your posts, it shouldn’t show up. However, if you realize a mistake 40 minutes after it shows up and update it, then you have created a duplicate post. The reason is because 30 minutes after you publish the post, the feed reader is updated and since you updated your post after that first 30 minute mark, at the next 30 minute interval, the feed reader is updated again causing it to show up as a new post in the feed reader. With the two posts that had duplicated, I realized that I had updated them even 3-4 hours later and that could have been the reason they were duplicated.
How to Avoid Duplicate Posts
The most simple response would be to re-read your posts several times before posting them because that would be sort of like “prevention” where you correct a mistake before it is too late. However, if you have already published your post then the only way to ensure that your post won’t be duplicated is to update the changes as soon as possible so that you aren’t past the 30 minute update interval. The intervals may vary for different feed readers but I doubt that most of them read a blog quicker than a 10 minute interval so that should give you plenty of time go update a post before it is updated in the feed readers.
Backdated Posts
What happens when you backdate a post is that you take a post you wrote today on July 17th and backdate it to July 13th however, since your feed has detected that post today, it will display that post as though it was posted today. Sometimes, I create draft posts and don’t publish them till later, but that is forward-dating and that is not a concern. If you ever write a post today and change the post timestamp to 2 days ago, the feed reader will always display that post as if it was a new post for today.
So this was one of the first case studies that I have done on the blog and I hope you liked reading it. If you have any comments I would love to hear them!
That’s funny, I just did a post about the benefit of editing old posts!
I’ll have to go back and see if I’ve duplicated any in my feed over the past months.
I read your post and i do see the benefit and what you said is exactly right. If you have an old post with content that needs updating then you can do so and the feed reader will actually pick it up as a brand new post, which is what you would like, however, if i make a post today and go back later tonight to correct a few spelling errors then it will show up as a duplicate post and because the changes were made so close by it will actually show up one after the other. In your case, if you update a post that is a month old, the posts wont show up one after the other! I will see if your feed displays any duplicate posts!