Dropdown Boxes - Page 4
December 10, 2001
A small number of options usually presents few problems. Large
numbers are more dangerous territory. A common error is excluding
an option that users would like to select. For example does your
list of countries include the Caribbean island of Aruba, and the
principality of Monaco in Europe? Does your list of US state
abbreviations include "not US" for international users, and if
you do a lot of international business, is it near the top, so
they don't have to do a lot of scrolling?
Dropdown boxes are an area where usability experts and the Web's
most popular sites often part company. Some usability experts
(and some users) complain about the clumsiness of long dropdown
lists — for countries and even for dates. Yet you'll find
them on sites that are well known for good usability.
What those top sites have discovered is that users are pretty
dumb, or at least not great at filling in country and date text
boxes in a way that computers can understand. If they offer text
boxes, the error rates go way up, and that's worse than the mere
clumsiness of long dropdowns.
But do remember that whenever you use a dropdown box you're
taking control away from the user, which is generally a bad idea.
You are restricting them and refusing to accept responses they
might prefer to give.
Since most people don't know that keyboard arrow keys work on
dropdown boxes, you also have to consider whether your layout
forces your user to keep switching from keyboard to mouse.
Whenever possible, you should avoid these switches. If your
overall layout permits it, try to group mouse operations
(checkboxes, radio buttons, dropdowns) together and keyboard
operations (text fields) together.
Text Fields
Users generally prefer these to dropdowns, assuming the computer
at the other end can understand the content and won't come up
with an error message.
The displayed size of a text field is important because it give
users a clue what size answer is expected. If they run out of
space, they'll wonder if they're doing something wrong. This can
be used to advantage. If you're using a text box to accept US
State abbreviations, you can set the displayed box size to two
characters, while at the same time setting a high maximum field
size so the box still works if a full State name is typed in.
The issue of dividing up address boxes into separate lines,
usually labelled Address Line 1, Address Line 2, and so on, is
another tricky one. Some usability experts prefer to see the
address lines combined as single text field. The problem here is
that you must then disable the Enter key so it can be used as a
carriage return without submitting the form, and point out to the
user that you've done this, so they have the confidence to press
it. Once again, the common practice of splitting address lines,
as used on almost all the top sites, creates some apparent
clumsiness but is probably the neatest solution when compared to
the alternatives.
Do make sure your system can accept spaces between numbers. Users
will often add spaces when entering telephone and credit card
numbers. If these generate an error, they'll think your computers
are pretty dumb, or, if they're a bit more knowledgeable, that
your programmers are pretty dumb.
It's this kind of attention to detail, and programming effort,
that separates good forms from bad ones, and leaves your visitor
with their final impression of whether your HTML forms were a
painful battleground, or simply a mildly tedious experience. That
final impression, which is their judgement on your usability,
could easily determine whether they come back again.
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