Control Choice - Do you use checkboxes instead of multi-select dropdowns?

For multiple items selection, multi-select dropdown listboxes have a number of behavioral quirks that make it difficult for users to get used to them:

• They require users to know that you select more than one entry by holding down the Ctrl key
• They lose all selections if you click in the wrong place
• You can't tell if a Listbox is single-select or multi-select at first glance

Note: It is OK and recommended to use dropdown lists for single item selection, when there is no more than 10 options.

Checked Listboxes are the ideal alternative for multiple items selections. They're much more pleasant to use and are a good deal more intuitive - compare to the list above. Checked Listboxes tell users immediately that they have the ability choose multiple options.

• In ASP.NET, use System.Web.UI.WebControls.CheckBoxList. If you're having problems with there being too many items in the list, use a scrolling div
• In Windows Forms, use System.Windows.Forms.CheckedListBox

We have a program called SSW Code Auditor to check for this rule.