Human-computer Interaction

Source: P.M.Heathcote

A Level ICT

Chapter 61

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Computers in the workplace

Applying ergonomics to the office environment: Lighting

chosen for brightness, contrast, glare, blinds etc Furniture

must be comfortable and adjustable Environmental considerations

energy-efficient computer systems

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Vision important information should not be displayed in

blue text - the eye is less sensitive to blue 8% of males and 1% of females are colour-blind no interface should depend on everyone being

able to distinguish colours Hearing

Sound is commonly used for warnings e.g. illegal operation; Mac SonicFinder uses ‘auditory icons’

Psychological factors VisionVision

important information should not be displayed in important information should not be displayed in blue text - the eye is less sensitive to blueblue text - the eye is less sensitive to blue

8% of males and 1% of females are colour-blind8% of males and 1% of females are colour-blind no interface should depend on everyone being no interface should depend on everyone being

able to distinguish coloursable to distinguish colours HearingHearing

Sound is commonly used for warnings e.g. illegal Sound is commonly used for warnings e.g. illegal operation; Mac SonicFinder uses ‘auditory icons’operation; Mac SonicFinder uses ‘auditory icons’

VisionVision important information should not be displayed in important information should not be displayed in

blue text - the eye is less sensitive to blueblue text - the eye is less sensitive to blue 8% of males and 1% of females are colour-blind8% of males and 1% of females are colour-blind no interface should depend on everyone being no interface should depend on everyone being

able to distinguish coloursable to distinguish colours HearingHearing

Sound is commonly used for warnings e.g. illegal Sound is commonly used for warnings e.g. illegal operation; Mac SonicFinder uses ‘auditory icons’operation; Mac SonicFinder uses ‘auditory icons’

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Psychological factors - continued

Touch important in keyboard and mouse design.

Movement users may find it difficult to manipulate small

objects so targets should be reasonably large Memory

present information intuitively, in easily-memorised portions

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Designing good software Study software design to see what makes it good:

observe people interacting with computers what do they find easy which parts lead them to make more errors

Human-Computer Interaction (HCI) design cycle

Participate in

Studied by

Talk to and observe

Reveals

Contributes to

Users

Usability testing

Design Weaknesses

Design Improvements

HCI Researchers

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Good User Interfaces Provide:

Help for novice users Short cuts for experts Meaningful images Consistent behaviour Clear, helpful error messages Uncluttered screens with effective use of colour and text that is

easy to read. Text vs Graphics

GUIs are generally easier to use Sometimes it is quicker for an expert to type commands Overuse of GUIs can slow the system down