What's the reason behind UX/UI Design to use (9+) and not showing exact amount instead?

Question

I was presenting some design work for our teams new bookmark system where you can effectively bookmark your favorite games and in the design we show (9+) if the user has bookmarked more than 9 items instead of 10, 11, 25, etc we just have it as 9+.

Also as a way to save character space in our design. (9+) versus (225), etc. I see this pattern in video games a lot especially in F2P mobile games, and sometimes on websites.

So the question I have is I can't remember the reasoning behind this but I remember when I was studying computer science back in Uni and HCI that this was a weird topic to show 9+ and not the full number. My team is fine with the 9+ reasoning but I can't for the life of me find any information on this type of design pattern and would love to just get info on it.

Answer 1

As it can be displayed in various forms according to it's use case here, it can be displayed either 99+ or 999+ like in your case preferred as 9+.

Depending on the context given above, mainly two factors seem relatable here;

• The first and the foremost one is, there's a limited space for the digits on the display to show the exact number where it's enourmously big like thousands/millions.

• Secondly, it's mostly preference depending on the context (of the environment, the notification type, personas, etc.) whether it's less or more than the number represented as an ideally possible number. So that, it's not matter to display exact number, other than informing users as it's specifically more than a bunch of them.

Use case:

For making a brief more clearer, consider a mailing mobile app for instance. Let's say users expected to have ideally around a couple of new e-mails to hundreds of them in their inboxes. Besides the mobile app icon has a specific width and height so that it can to say, only hold 4 digits as a badge for notifications on top of it.

In this case, setting the notifications badge up to 999+ is the optimal choice for both providing an icon on mobile that seems looking good and informing users enough to let them it's time to take a look at it since it's more than ideally expected.

Best practice: Besides an example use case above, it's also beneficial to know how it's preferred to be displayed. Again let's consider a case that ideal users expected to have a couple of notifications, and we're looking for a better solution to display notifications when it has reached 5, 6, 7, etc digits. Like if it's making no sense to let users know about the exact number of this notification type, it's preferred to be shown as 9.999+, 99.999+ or 999.999+ instead.

Answer 2

Your question reminded me of the once held belief of the 7 plus/minus 2 myth that many people used to talk about (UX Myth #23 Choices should always be limited to 7+/-2), but I am pretty sure that this doesn't have anything to do with the decisions.

When it comes to the display of values, there are usually the constraints of the user interface and also the psychological or cognitive rationale of why you would limit or constrain the value. There is no particular reason to suggest why this figure of 9 applies to bookmarks, other than maybe once it gets to about 10 then people probably need a better way to manage it other than leave it open in their browser and try to find individual ones.

However, rather than using an assumption to set this seemingly important or at least useful figure, I would suggest trying to do some research.