Monday, November 06, 2006

67% vs 66.7%

In KPDF in the zoom combo we had
in okular in the zoom combo we fixed it to
but our usability dude still thinks
would be better as it "aligns" things visually. What do you say?


Florian Grässle said...

Just to give you an impression of what i mean, compare

Anonymous said...

I agree with usability guys 66% is easier to understand compared to 66.7% .

Lengau said...

I, too agree with the usability guys. 67% looks a lot smoother than 66.7%. It's not a huge difference, but one of those tiny things that just makes it easier on the eyes.

Anonymous said...

What about a slider?

Aaron J. Seigo said...

for viewing (as opposed to, say, laying something out for print), .3% doesn't matter. in fact, i doubt few would or could even notice the difference.

"hold on! that's not 67%, that's 66.6%!"

perhaps just drops the decimal instead of rounding, because 66% "says" 2/3rds whereas 67% seems a bit random ;)

halcyon.corsair said...

Who cares about the percentage number? How about we fix the real problem with zooming, and put the Zoom in and Zoom out buttons on the same size of the zoom box, rather than on opposite sides!

manu said...

I would really go for 66%. It looks much more "standard" than 67% or 66.7%. 66% is a common way to write 2/3. 67% only looks weird and unexpected.

Anonymous said...

I would agree with usability guys.
As a user I don't really care about decimal precision :-).
Let it be 66% or 67% - i don't care. I just need some number which indacates that this zoom is between 50% and 75% ;)


pinotree said...

@halcyon.corsair: i just fixed that, it was pretty easy as our usability experts already talked and decided about this issue. Now the zoom actions in the okular toolbar look like:
[zoom combo] [zoom out] [zoom in]
Thanks for bringing this to our attention! :)

Anonymous said...

66%? 67%? How about we go in the middle and take 66.5%? :)

I agree, 66% is better. Technicall, 66.7% is 'correct', and 67% is a good approximation, but 66% just implies 2/3 better.

If the user wants to be precise, they can type in their own damn value.

leo said...

66% is definitely better than 67%.
I also agree that any half percentage point of zoom is not important in a document viewer. I assume you can still enter your own zoom percentage?

As an anecdote, Adobe Reader on windows does this probably in the worst possible way. The zoom dropdown has no levels between 50% and 100%, and pressing the zoom buttons gives these steps: 50%, 65%, 66.67%, 75%, 100%.
Apparently they let a monkey choose those zoom levels.

Anonymous said...

I vote for 66%.

Anonymous said...

me votes for 66%, too. sound just right.

Anonymous said...

I agree with 66%, it's more easy to understand.

But will it still be possible to choose 73% or 65%?

I think it would be nice that the combo box would show the "default presets" (25% 33% 50% 66% ...) but somehow allow the user to choose a more fine grid of zooms.

Anonymous said...

I prefer 67%.

pinotree said...

@ anyone: i remember that - like in kpdf - the combo box is editable, so you can always type in your wanted zoom level.

Anonymous said...


Anonymous said...

Right now, it's already a rounded number. Rounding the number to 67% shouldn't be too bad.

I very much prefer 67% over 66%, though. To me, 67% looks more professional. Why? Because anyone who has basic math skills knows the percentage that's equal to 2/3rds is 67% (when rounded to zero decimal places).

The people that know will get annoyed by 66%, the people that don't won't get annoyed either way.

It's things like this that, when done incorrectly according to my view, will personally make me think less of an app, nofi.

Quintesse said...

66% for me too, the moment I saw the list (all 3 of them) I thought "yech, isn't there a better way to do this?".

And for 67% being mathematically more correct, sure, but it's just an amount, there's no real reason why it should be 2/3 exactly.

Even better, let's get rid of 25% and 75%, just multiples of 10% should be enough.

Anonymous said...

66% is the way to go. Decimal point precision is silly for something like this. And 66% in my brain is more like 2/3 than 67%.


ricard said...

@ pinotree: you're right, I should have been more precise. I meant to set a finer resolution zoom in a more interactive way, like using the mouse wheel or dragging a slider and seeing immediately how the control you're modifying actually modifies the document you're viewing. (even if that "preview" zoom is done in a pixelized way, for technical reasons).

The reason why I say this is that when a user wants to zoom in a document normally he doesn't care about numbers but rather if it's big or small enough for him to read (this is obviously not the case when printing to paper, but this is a different story)

@ those who prefer 67% because it's the correct round(2/3*100): I don't think that showing 66% is "wrong" if the actual zoom that okular will be applying is 66.0% and not 2/3. So I don't think this is an strong argument against 66%.

For me it's visually faster to relate 66% to 2/3 than 67% (though this might depend a lot on the user).

Louis said...

Another vote for 66%. My mind also relates 66% to 2/3. Either way, having no decimals is an improvement. Thanks.

nidi said...

My vote to 67%, because:

You round it, be it 66.7% or 67%. Using 67% is more logical, because you also use 50%, not 50.0%

Just my 2%.

Anonymous said...

Of course, your usability guy is correct. Sheesh. What's your problem, stop wasting our time.

flai said...

Usability wins!!!

BTW 66% is visually more appealing.

Kevin Kofler said...

As a Mathematician, I vote for "2/3" or "66 2/3%", everything else is just a crappy approximation. :-p If it really has to be a decimal, then I vote for 66.67% or even more '6' digits.

Anonymous said...

I think your usability guy is right. Duh. However, I think ratios would be even better: like 1:1, 3:4, 2:3, 1:2, 1:3, etc. They can align well as be exact.

Daniel "Suslik" D. said...

The best values are "Page full width" and "Page full height"

The rest will be blindly slected by + / - buttons anyway.


Anonymous said...

agree on anonimous: get rid of %! scale factors (1:1 (100%), 1:2 (50%), 2:3 (66.(6)%, 3:4 (75%), ...) are faaaaar better

Florian Grässle said...

@the x:y anonymous:
1:2 has its problems since the dropdown as of now is also a status widget. If you zoom with the zoom in/out buttons the zoom percentage gets adjusted. It may give you e.g. 112% - which is easy to set into the right order. In the dropdown it's between 100% and 125%. If you choose 1:3, 1:2, 1:1, 2:1 and so on, where should the current level go and what should it look like? 112% is far easier to set in order and to build a mental model of than 9:8.

The GIMP btw uses the x:y approach and lists the current custom zoom level at the end as "other". You then have to compare it with the other zoom levels and find out yourself what to choose to increase or decrease the zoom level. That's a way to solve the problem but a rather bad one I guess.

Replacing the current system is not as easy as it seems ;)

Anonymous said...

Whether it's 66% or 67% isn't really that relevant in my opinion (although if you display 33% and 66% then you should also have 99% instead of 100%, so I tend to prefer 67% ;-)

However I'm strongly opposed to the ratio format which has already suggested, because it's hard to understand and easy to get wrong.
It's not only that 1:2 and 2:1 can be hard to distinguish but it's also unclear whether that is meant to be a division (i.e. 1:2 = 50%) or a true ratio (1:2 = 33%).

I have my problems with the zoom in and zoom out buttons being on the same side. Why? Because given that a combobox alone isn't self-explaining it's rather hard to relate a single combobox to the zoom level. That's why people tend to accompaign the combobox by the "+" and "-" toolbar buttons on each side which saves them a "Zoom:" label as the purpose of the combobox becomes immediately apparent without having to attach a "Zoom:" label.

I also agree with Cristian that the steps at large should be a good compromise between equidistant and logarithmic. Magnifying the canvas logarithmic feels much more natural and less tedious.

Anonymous said...

Why is nobody proposing s.t. like
and while we are at it keep the numbers aligned at the point.

dehn said...

I would go for this layout:
[Zoom slider][Fit to page][Fit to width]

Remove the +/- buttons. Using discrete steps when reading a document doesn't make sense, so a slider is a better choice. But "Fit to page" and "Fit to width" are handy zoom levels so they sould stay.

Matthew W. S. Bell said...

You should format the numbers you are displaying consistently; so pick a number of decimal places and stick with it. Much in the same manner as when you are displaying data in a spreadsheet.

However, I'm more inclined to say that people don't care what percentage or ratio it is; they just want it to be big enough to read or examine what they want.

The only case where I can think that I would care about specific numbers, is if I were trying to set the document so that it appears as it's actual physical size. It would be annoying if I couldn't set a specific zoom if I needed to though.

Anonymous said...

WOAH, step back a moment. We are displaying this on a monitor. somewhere between 90 and 100 dots per inch. If you do the math, you will discover that many monitors is not capable of displaying a true 2/3rds. (96 dpi is the only one that works, out, as I recall monitors are traditionally 92) Then of course most monitors are not really the states size. I've run the standard 1024x768 on monitors from 12 inchs to 19. By the "standard" only a 14 inch monitor can display this correctly.

The short of my response, is you are displaying more precision than you have, even in the ideal case.