Things to consider when writing for touch screen?

Question

I\'m starting a new project which involves developing an interface for a machine that measures wedge and roundness of lenses and stores the information in a database and reports

Answer 1

If you decide to put in analog controls (scrollbars, rotation widgets, etc) be sure to put in a digital control also. Some companies think that a touch screen means perfect control over something with your fingers. In real life, this translates to minutes of frustration trying to fix a number that's just a little off.

Answer 2

The larger gui elements is the major thing. But it applies to all elements, scroll bars, tabs and even text fields.

The other major thing that I can think of, it's hard for the user to right click. So things that require a right click should be avoided, context menus are the only thing that comes to mind at the moment.

Answer 3

The other obvious one is that there's no equivalent of pointer 'hover'. Not that that affects many apps though.

Answer 4

I wrote my own set of controls for a POS application designed specifically to be touchscreen friendly.

Remember to allow enough real estate for stubby fingers and talons. In our application the users can have these manicures that necessitate them to use the pad of their finger instead of the tip. This means that you need to allow more space for activation areas than you would normally consider in any other type of application.

I would also recommend that you accommodate yourself as a programmer from a testing standpoint and from the point of view that things change and there may need to be a keyboard/mouse attached to a non-touch workstation. I cannot tell you how many times I went to touch my flat panel LCD expecting something to happen, before remembering that I had to use the mouse.

Answer 5

Make sure to read your basic UI principles like Fitz law (The time to acquire a target is a function of the distance to and size of the target).

Also consider whether or not the device is stationary or not when it is in use (e.g., like a palmpilot or iphone), research shows that you must accomodate that into your design.

Answer 6

The other responses are pretty good, but are you totally sure that a touch screen would actually be easier to use? There are a lot of devices where a touch screen actually makes them much harder to use, not easier. The main problem is that you can't use the device when you're not looking at it. If users are going to be doing a lot of repetitive actions, a keyboard could be a lot more efficient.

Also, a touch screen might be a lot harder to use by someone with a disability, if you think there's even a small chance that could happen.