[IxDA Discuss] Input Field Lengths

[Jim Drew]

>From: valerie at valeriefranek.com
>
>In my experience, the guideline for determining the size of input fields
>is to use a size similar to the information that the user will be
>entering.  So, a field for a 16-digit credit card number should be about
>16 characters long; a field for a 3-digit CVV code should be about 3
>digits long.  For data that is not so determined (email address, proper
>names), an average or estimate length should be used. 

I'm sure you would do so anyway, but just to note: you should use an above average length, not an average one.  With an average one, half of all entries would exceed the limits, and you really want closer to only 15% (number pulled from my ear) to do that.


>However, the standards I'm reviewing suggest that all input fields should
>have the same width, so as to provide visual consistency within the page.
>The size is determined by an average length across all fields.  The
>argument for this is to make the page easier on the eyes, so that the
>field labels and input fields aren't creating a jagged effect.  It seems
>to me that this approach is more geared towards the visual or graphic
>design side of thigns though, rather than focusing on usability.

What I would say it is geared toward is "make it look like a paper form": everything fits on a rectangle, squeezed into a mass of both sameness and lack of readability.  (How many times have you hit the reverse of the problem you're having, with a paper form: only 1/2 inch to put in a city name like Coeur d'Alene or San Bernardino, because something had to be squeezed down.)

You are not/may not need to be confined to a set page size with an app, so the needs of paper forms shouldn't constrain you.  Users may actually be grateful to have "breathing room" in the form.

One answer may be to group things with borders or boxes.  This allows you to have sectional uniformity with flexibility inside the sections, plus the section headers will give extra hints to the user.

-- Jim Drew
   Seattle, WA