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User Interface Design and Ergonomics - National Open University of ...

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3.5 USER INTERFACE MODALITIES AND MODES<br />

A modality is a path <strong>of</strong> communication employed by the user interface to carry input <strong>and</strong><br />

output. Examples <strong>of</strong> modalities:<br />

Input — allowing the users to manipulate a system. For example the computer keyboard<br />

allows the user to enter typed text, digitizing tablet allows the user to create free-form<br />

drawing<br />

Output — allowing the system to indicate the effects <strong>of</strong> the users' manipulation. For<br />

example the computer monitor allows the system to display text <strong>and</strong> graphics (vision<br />

modality), loudspeaker allows the system to produce sound (auditory modality)<br />

The user interface may employ several redundant input modalities <strong>and</strong> output modalities,<br />

allowing the user to choose which ones to use for interaction.<br />

A mode is a distinct method <strong>of</strong> operation within a computer program, in which the same<br />

input can produce different perceived results depending <strong>of</strong> the state <strong>of</strong> the computer<br />

program. Heavy use <strong>of</strong> modes <strong>of</strong>ten reduces the usability <strong>of</strong> a user interface, as the user<br />

must expend effort to remember current mode states, <strong>and</strong> switch between mode states as<br />

necessary.<br />

4.0 CONCLUSION<br />

In this unit, you have been introduced to the fundamental concepts user interface. You<br />

have also learnt the history <strong>and</strong> significance <strong>of</strong> user interface design.<br />

5.0 SUMMARY<br />

You must have learnt the following in this unit:-<br />

The introduction <strong>of</strong> user interface which is the aggregate <strong>of</strong> means by which users<br />

interact with a particular machine, device, computer program or any other<br />

complex tool.<br />

The study <strong>of</strong> the various types <strong>of</strong> user interface design which includes graphical<br />

user interfaces, web-based user interfaces, comm<strong>and</strong> line interfaces e.t.c<br />

The history <strong>of</strong> user interfaces which can be divided into batch interface,<br />

comm<strong>and</strong>-line user interface <strong>and</strong> graphical user interface.<br />

The modality <strong>of</strong> a user interface which is a path <strong>of</strong> communication employed by<br />

the user interface to carry input <strong>and</strong> output.<br />

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