Human and Computer Interaction (H.C.I.) &Communication Skills Lecture (4) Prepared by Dr. Dunia Hamid Hameed

4. Form-Fill Interfaces (Input/Output Forms) Form-fill interfaces consist of onscreen forms or Web-based forms displaying fields containing data items or parameters that need to be communicated to the user. This interface technique is also known as a form-based method and input/output forms.

An example of the form-fill interface

The chief advantage of the input/output form interface is that the printed version of the filled-in form provides excellent documentation. Web-based forms push the responsibility for accuracy to the user and make the form available for completion and submission on a 24-hour, 7-day-a-week, worldwide basis.

There are few disadvantages to input/output forms There are few disadvantages to input/output forms. The main drawback is that users experienced with the system or application may become impatient with input/output forms and may want more efficient ways to enter data.

5. Command - Language Interfaces A command-language interface allows the user to control the application with a series of keystrokes, commands, phrases, or some sequence of these three methods.

Command-language interfaces

Command languages require memorization of syntax rules that may prove to be obstacles for inexperienced users. Experienced users tend to prefer command languages, possibly because of their faster completion time.

6. Graphical User Interfaces The key to graphical user interfaces (GUIs) is the constant feedback on task accomplishment that they provide to users. Continuous feedback on the manipulated object means that changes or reversals in operations can be made quickly, without incurring error messages.

7. Other User Interfaces These interfaces include pointing devices such as the stylus, touch- sensitive screens, and speech recognition and synthesis.

The stylus (a small pointed stick that resembles a pen) is becoming popular because of new handwriting recognition software for personal digital assistants (PDAs) and mobile phones.

A tablet PC is a notebook computer with a stylus- or touch-sensitive display. It is much more powerful than a handheld computer but weighs considerably more. Both handhelds and tablet PCs can be equipped with built-in Wi-Fi or Bluetooth® communication. Touch- sensitive displays allow a user to use a finger to activate the display.

With voice recognition, the user speaks to the computer, and the system is able to recognize an individual’s vocal signals, convert them, and store the input. Voice recognition inventory systems are already in operation, and automobiles now feature voice input systems that respond to a driver’s voice commands to navigate or to change the radio station.

An advantage of voice recognition systems is that they can speed data entry enormously, and free the user’s hands for other tasks (for example, driving). Speech input adds still another dimension to the PC. It is now possible to add equipment and software that allows a PC user to speak commands such as “open file” or “save file” to avoid using the keyboard or mouse.

When evaluating the interfaces you have chosen, keep some standards in mind: 1. The necessary training period for users should be acceptably short. 2. Early in their training, users should be able to enter commands without thinking about them or without referring to a help menu or manual. Keeping interfaces consistent throughout applications can help in this regard.

3. The interface should be seamless so that errors are few and those that do occur are not occurring because of poor design. 4. The time that users and the system need to bounce back from errors should be short. 5. Infrequent users should be able to relearn the system quickly.