Touchscreens are replacing keypads because of their intuitive operation, software flexibility, and space and cost savings. This change offers many benefits and solves many human-device interface problems. But the loss of tactile feedback that users experience when pressing a mechanical button creates other human-device interface problems. Moreover, some users like to use systems that provide tactile response.
Some usability guidelines
- There should be clear and direct navigation to return to the Home and the Main menu.
- Minimise the steps to access the basic functions such as answering a call, instant messaging, viewing messages, accessing the internet etc.
- The touch response lag should be minimum.
- Ensure that the locking mechanism is intuitive, Provide an automatic lock facility.
- If devices is having only the virtual keypad, try to match the speed and accuracy offered by traditional keypads as far as feasible.
- For the user input, its better to provide a virtual QWERTY keyboard.
- Make use of familiar icons so that the users can associate with them.
- In a designs for touch screen interface, UI elements used for interaction must be large enough for users to easily select with their thumbs. if UI elements is very small then user may feel inconvinience in using application.
- Touchscreens are not well suited for data entry. So provides a virtual keypads for large data entry, for example the application which take feed back from users.
- Make sure the activation area for each interaction element is as large as its corresponding visual representation.
- Entering values can become very tedious on touchscreens. Value entry should be restricted to few values. The basic interaction modes are: Clicking repeatedly on certain controls (e.g. to increment or decrement volume control), Dragging sliders or similar controls.
- keep small items far enough apart so that they are as easy as possible to select accurately.