Should I use a drop-down? Four steps for choosing form elements on the Web
You are designing a form for the Web and you want to make it easy for your form user to choose answers to your questions. There are five HTML form elements available: drop-down box, radio buttons, check boxes, type-in box and hyperlinks. Which one is the most usable?
Sarah Miller and Caroline Jarrett present a four-step process for choosing the appropriate element in this paper (pdf format, 58Kb).