I have a simple rule when it comes to the use of drop downs in forms: use them only when the list of options is exhaustive, mutually exclusive, and the drop down contains every option.
Online drop downs in forms often fail to follow this rule. They are often used, for example, to list forms of address (sometimes known as honorifics or salutations). I recently came across a form on a publisher’s site, whose range includes many books about British military history, containing 37 forms of address, including many military and church titles, as well as the more usual Mr/Mrs/Miss/Ms/Dr/Prof. selection.
This drop down was already long, but by no means exhaustive. I have previously found a drop down of forms of address in an online form with 224 entries, stemming from civil life, the armed services, religions, nobility, governments, academia and the judiciary. A list this long confuses and frustrate users, and even a list of forms of address that long breaks the rule in that it is not an exhaustive list and the options are not mutually exclusive. I have collated lists of several thousand forms of address in use, without actively looking for them, and there will always be people whose form of address is not on a drop down’s list. Equally, were my title to be Professor Sir, how would I indicate this, when I may only choose one entry from the list?
When working internationally, you can’t restrict your list to results from only one country. There are many hundreds of academic forms of address used in German-speaking countries, for example. In other countries the honorific is suffixed rather than prefixed to the name, and may be concatenated to the name. With the number of possible forms of address in the thousands, and without them being mutually exclusive, drops downs can never be used for them in forms.
There are data elements which would appear to be more suited to drop downs. Country name, for example. But how do we define a country? Is Taiwan to be included in the list? Or Kosovo? Do we write “Macedonia” and upset the Greeks, or “FYR of Macedonia” and upset the Macedonians? What about Transdniestria, Northern Cyprus, Somaliland and Nagorno-Karabakh? Should overseas’ territories be included? Or those parts of a country which are overseas?
I used to suggest that gender was a question that would have allowed a drop down to be used. After all, we’re all either male or female, right? Well, this is an area where I have also had to update my views. After all, we might be transsexual (MTF or FTM), intergender, intersexual, or something else that I haven’t come across yet.
When using drop downs in forms, remember that the number of options have to be limited, complete and mutually exclusive. And if you think they are, check again, just to be sure. You’ll be glad you did!