Forms are essential parts of user interface whether you are working on mobile apps or web based tools. They are the best source of user interaction. User provides his information and input through forms and system interprets this information to fulfill user requests.
There are certain items that make a form usable including input controls, input validation, error handling and user feedback.
Two important input controls are radio buttons and drop-down menus. Both of them can be used interchangeably when an input is required from user. However, if we study about the usability of these controls, it becomes apparent that radio buttons and drop-downs should be used in certain scenarios to make it easier for user to select a given input.
Below are few rules based on this usability study that will help you to decide about one of these controls while designing a form.
Use Radio Buttons
Rule#1: When You Want to Emphasize Options
There can be multiple cases where you want to emphasize options:
- There is no clear default or recommended option.
- You want user to read all options.
- The options are unfamiliar to user and there is less or no chance that he can predict them.
In example, using a drop-down menu does not seem good as default option does not give a clue about other options.
Rule#2: When You Have Less Than 5 Options
Lesser options are good to place side by side so that:
- User scans the option easily and quickly.
- He provides quick response instead of opening a drop-down menu and select from multiple options.
It is better to use radio buttons when user has to select from 2 to 4 options, as shown in example.
Rule#3: When Comparison of Options Needs to Make Clear
Comparable options are good to place side by side because:
- User can see them at a glance and compare them easily.
- Comparing and deciding about an option from a drop-down menu takes time.
- User has to open the menu and compare options each time he wants to review the selected option.
A good example above is about selection of subscription plan where user has to make a serious decision.
Rule#4: When Visibility and Quick Response Is A Priority
Clear visibility and quick scan of options is more understandable for user.
- For longer forms, it becomes easier and quicker to scan the options and mark the required ones.
- Clicking a drop-down each time to select something takes a lot of time.
It is obvious from given example that long forms provide good user experience when all select-able options are visible to user.
Use Drop-Down Menus
Rule#5: When Default Option Is The Recommended Option
Viewing only the recommended option makes easier for user to decide the selection because:
- Displaying all options will draw user’s attention.
- It is not encouraged for user to change the default option.
In example, there is no need to display all options as here is lesser chance for user to change the default option.
Rule#6: When A Large Number of Familiar Options Are Available
Large number of familiar options are encouraged to display in drop-down because:
- User can predict them easily.
- There is no need for him to see options side by side.
Rule#7: When You Have More Than 7 Options
Large number of options are not good to display side by side because:
- It becomes cluttered on UI if a pile of options is placed side by side. User can get confused while looking at them.
- It takes time to scan a large list of radio options.
Also, for a long drop-down, it is a good practice to provide a text box where user can type the option name and list displays filtered options only. This makes selection easier and quicker.
To enhance form’s user experience, it is very important to provide correct controls to take user’s input. Since forms can be very long with large number of options, it becomes tedious for user if he has to make extra clicks to fill his information. The given set of rules will help you to decide between two controls, radio buttons and drop-down menus, while designing your forms.