Human-computer Interaction Source: P.M.Heathcote A Level ICT Chapter 61

ICT5 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

ICT5 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 Vision Vision important information should not be displayed in blue text - the eye is less sensitive to blue 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 8% of males and 1% of females are colour-blind no interface should depend on everyone being able to distinguish colours no interface should depend on everyone being able to distinguish colours Hearing Hearing Sound is commonly used for warnings e.g. illegal operation; Mac SonicFinder uses ‘auditory icons’ Sound is commonly used for warnings e.g. illegal operation; Mac SonicFinder uses ‘auditory icons’ Vision Vision important information should not be displayed in blue text - the eye is less sensitive to blue 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 8% of males and 1% of females are colour-blind no interface should depend on everyone being able to distinguish colours no interface should depend on everyone being able to distinguish colours Hearing Hearing Sound is commonly used for warnings e.g. illegal operation; Mac SonicFinder uses ‘auditory icons’ Sound is commonly used for warnings e.g. illegal operation; Mac SonicFinder uses ‘auditory icons’

ICT5 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

ICT5 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

ICT5 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