Design considerations for touch screens – Part1

Touchscreens - The Future
Touchscreens are operated as city guides, in museums, at POS (point-of-sale)stations or as kiosks(standalone advertising booths with user interaction) and now in the recent have made way into homes in the form of DPFs and Multimedia phones. Interaction has to be simple and fast as Users are often untrained. This calls for a screen and interaction design, which is considerably different from normal user
interface design.

Interaction
Touchscreens are operated with a finger or stylus. Therefore, they provide a very direct interaction - the most direct interaction that is possible on computers today. Touchscreens may be operated very fast for certain operations and require little or no training, if applications are designed adequately. For these reasons touchscreens have many uses, especially for untrained users. Many people believe that
touchscreens will replace keyboard and mouse in the future.

The Ultimate Judge is the User!
These preliminary design guidelines for touchscreens take the characteristics of touchscreens, their advantages and disadvantages, into account. Of course, these guidelines will be refined, as our experience with touchscreens grows. The ultimate judge, however, is the user. As ELO Touch Systems quote in their guidelines:

·Testing a touchscreen application on focus groups will disclose the areas that need improvement.
·If anyone pauses in confusion for even a moment, think how to improve the application.

Summary of Touchscreen Characteristics
·Speed: high
·Accuracy: low (finger), high (pen)
·Speed control: yes
·Continuous movement: yes
·Directness: direction, distance, speed
·Fatigue: high
·Footprint: no
·Best uses: point, select

Uses for Touchscreens
Best Suited to Applications Where...
·Opportunity for training is low
·Frequency of use is low
·Accurate positioning is not required
·Little or no text or numerical input is required
·Desk space is at a premium
·The environment may be chemically or otherwise "aggressive"

Not Suited to Applications...
·Requiring training/trained users
·With high-frequency use
·Requiring accuracy
·Requiring a lot of typing

Typical Touchscreen Systems
·Public information systems: Museums, city guides
·Kiosk systems: Advertising, product information
·Systems requiring pointing and selection only

Golden Rules
Speed: Make your application run fast. Speedy systems also reduce vandalism.
Intutiveness: Try to make the application intuitive.
Choices: Limit choices.
Guidance: Guide the user as much as possible.
Testing: Testing a touchscreen application on focus groups will disclose the areas that need improvement. If anyone pauses in confusion for even a moment, think how to improve the application.

This post is contributed by Mallikarjun