# Should Up Arrow increase the value or decrease it?

So we are a team of students and we are developing an app. We can't decided whether an UP ARROW should increase the value or decrease it. We are hoping there are some programming standards or guides covering that topic, and we are hoping someone will provide us with a link.

Simple case:

Imagine a simple counter with three fields (012 for example). Now let's assume first field is active and user can use UP and DOWN arrows to change the value of currently active field. Now half of the team thinks it is more intuitive that UP arrow changes value from 0 to 1, and the other half things DOWN arrow should do that.

In the end it is not too difficult for user to figure out the logic but still if the whole population is like our team, than half of the users will find the solution intuitive and the other half will dislike it. In other words: we are losing 50 % of potential customers before even starting.

So are there any standards/guides covering that?

• Why do they think the down arrow should increment the value? It seems such an odd idea that there must be some strange logic to it. Commented Jul 3, 2018 at 13:28

You should consider kicking the people out of your team that think "arrow down" should increase the number from 0 to 1.

Of course arrow up should increase and arrow down should decrease, i don't understand how someone would argue that.

You can use "+" and "-" to make it more obvious though.

• Firefox and Chrome thinks the same way (at least, in French): they add an "up arrow" by the side of every `<input type="number">` HTML, and that up arrow increases its value. Commented Jul 3, 2018 at 13:11

This doesn't answer what you should do, but offers one possible reason as to why so many people think down-arrow should increase the value. This could be due to the way a standard drop-down selector works:

If the selector has focus, then using down-arrow will increase the value of the field and using up-arrow will decrease the value of the field.

The obvious answer is to not use a drop-down selector for pure numerical input, but I've seen many sites that do do so. And even if you don't, some people (50% in your case) may already be conditioned to expect that down-arrow will increase the value.

In some ways, it's akin to whether up/down-arrows should move content up or down in a scroll-able area. For most applications, we think of the arrows as moving the viewport, so up-arrow moves the viewport up, allowing us to see earlier parts of the document/content. It could have been just as intuitive to have the arrows move the content, so up-arrow moves the content up, allowing us to see later parts of the document/content.

If your application needs to use arrows, you can try to use orientations conveniently in the controls.

For example for Vote UP a question, the arrow is put in the top of control, this show the obvious function for increase the value, and is more successful for the eyes than + and - (this last is a personal opinion)

Just a thought:

I recommend using `+` and `-` instead of `>` and `<`, because `+` & `-` clearly indicates a increase or decrease of value, while the arrows create an ambiguity. Users might make a mistake on the first attempt if there is an up and down arrow.