# What is easy to perceive? Width or height?

Let say I have to show the difference between two values then what will be the best to show the values horizontally or vertically.

Edit: I need to know in which graph it would be easier to compare the distance between two dots.

• Can you please show images of what you mean by horizontal and vertical comparisons? Commented Aug 26, 2014 at 7:10
• Looking at it from a biological point of view I'd argue that humans have a more fine tuned ability to compare sizes in a vertical orientation. And why is that? Well, we can quite easily move on a horizontal plane without difficulty, meaning that if we see food somewhere on a horizontal plane we simply have to move over there to get it, no cognitive registration what so ever. But when we see food somewhere up in a tree we have to judge whether we think we can make the climb or not. Therefore I'd assume that humans are more capable of judging vertical distances rather than horizontal. Commented Aug 26, 2014 at 7:20

We scan the pages left to right, so jumping quickly from two specific pairs of dots will be much easier on option A than option B.

But please do your users a favor and connect the dots in some way. If all that they do is compare the distances in individual pairs, just connect the top dots with the bottom dot, instead of forcing their brain to imagine the line.

If the overall trend is also important (or more important), then draw lines connecting dots of the same type.

You can also do both, with or without filling the area between the top and bottom line.

This will have a much greater effect than horizontal vs vertical layout.

• There are formal conventions on how to graph data - so users will be used to the formats shown above. Commented Aug 26, 2014 at 12:25
• Okay here if I add no data is related to its next or previous data then what would you suggest? I think connecting lines the dots with the line is givig the sense of increment which is not the case here. Commented Aug 28, 2014 at 3:51
• Then I suggest going for the first option (vertical lines). You're afraid that drawing them with create an illusion of a trend and you're right, but from what I understand, your users are supposed to be familiar with the nature of the data and shouldn't be confused. Not connecting them for this reason is making the users work much harder just to avoid a vague possibility of them making a small and inconsequential one-time mistake. Commented Aug 28, 2014 at 5:09

Without some sort of context, I doubt you'll get an entirely useful answer...

That said, when stats are being compared on webpages using graphs (especially when comparing more than just two things), vertically presented horizontal bar graphs seem to work well and be most popular.

As a semi-random example: http://www.cpubenchmark.net/common_cpus.html

Imagine all that info arranged with vertical bars, listed across the page horizontally...