What is the technical reason that so many social media sites don't allow you to edit your text?

Question

A common complaint I hear about Facebook, Twitter, Ning and other social sites is that once a comment or post is made, it can't be edited.

I think this goes against one of the key goals of user experience: giving the user agency, or the ability to control what he does in the software.

Even on Stackexchange sites, you can only edit the comments for a certain amount of time.

Is the inability for so many web apps to not allow users to edit their writing a technical shortcoming or a "feature by design"?

Answer 1

Imagine this. I post a status update:

I finally finished our renovations!

Your comment is:

Great stuff! Congrats! I want to do that too.

And then I changed my original post:

I just kicked old lady.

Would you still stand by your comment? :)

Answer 2

Agency (as you define it: being able to control your data in the way that you want to) is in direct conflict with another key goal of user experiences:

Integrity

With social media it is historical integrity. Another goal that can be thwarted by "more agency" is operational integrity.

• Historical Integrity — This is Facebook, Twitter, even StackOverflow. @Yuriy addresses this with a great simple example. In addition, look at our own StackExchange software. You can edit your comments, right? Wrong. All you really have is an oh-sh** button. You have 5 minutes to rethink and reword what you typed in your comment, if you hit [Add Comment] too hastily, but then your comment is locked into history forever, (and marked as modified)...

  But you can delete it, and repost right? The important thing about this is that the new comment gets put after the rest of the conversation so that you can't hijack history out from under other participants.

• Operational Integrity — Look at iOS. One of the key tenets of iOS is a very tightly controlled system. This gives more control for Apple to give higher guarantees for many aspects of the experience: Battery life, crashing, viruses, malware (App Store approval process), etc.

  Some users don't want this. They go with Android. But this is one reason why task managers and advanced cache managers end up being popular on Android. It's a trade-off.

@twhitlock is correct that cache invalidation does introduce technical challenges.

But look at all the stuff Facebook does let you edit (every little bit of your profile, photo captions, tags, album captions, album arrangements, notes, events, friend lists, fine-control security settings, etc.) Facebook can handle the editing. They don't let you because it's a core part of their designed and controlled experience.

Answer 3

I think one of the technical answers is that it's easier to have read only data at large scale.

It's easier to have data that can only be added, that way you never have to worry about who has an old copy of the data. If you have to worry about editing then you get into different modes of data replication and either need to block read access when you are editing it, or allow it to update for the next read. This is a cache invalidation problem because in any large web site there is caching, and cache invalidation is one of the hard problems in computer science.

Answer 4

I think it's a feature by design.

First, from a communication point of view, the edit function provides a split in an exchange. If someone changes a start of a thread that has a long conversation so that it doesn't fit the conversation that resulted form it any more, there is a disjointedness.

I think that is why sites like StackOverflow require you have a certain amount of rep to be able to do it. The assumption is that you are trusted enough to not cause split like that.

Also, if you do not have the option to edit, it should (I don't think this is always the case) make you think about what you're about to write.

Answer 5

I always assumed it was purely a matter of scale - with 700 million users, tracking edits would be a big job!