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Case Study

HCI Principles

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1. Strive for consistency 2. Enable frequent users to use shortcuts 3. Offer informative feedback 4. Design dialogs to yield closure 5. Offer error prevention and simple error

handling 6. Permit easy reversal of actions 7. Support internal locus of control 8. Reduce short-term memory load

Shneiderman’s 8 Golden Rules

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Strive for ConsistencyConsistent sequence of

actions for similar situations

Identical Terminology (prompts, menus, help)

Consistent visual layout (fonts, color, etc.)

Exceptions: Confirmation of deletion No password echoing Limited

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Proper Feedback

Design Dialogs to Yield ClosureAction sequences should

have a beginning, middle, and end.

Feedback provides sense of accomplishment

Ex. Purchasing items via internet has a clearly defined step-by-step process

Permit easy reversal of actionsAs much as possible, actions

should be reversibleTrash canRelieves anxiety

Design decision should includeHistory sizeWhat does it mean to undo

something?Let the user know they can

reverse an action

Support Internal Locus of ControlExperiences operators want to feel in control

User is in charge of the interface Interface rapidly responds to the user

Builds anxiety and dissatisfaction Surprising interface actions Tedious actions Difficulty in obtaining necessary ability Difficulty in producing action Ex. Lag

Good rules: Avoid a causality, make users initiators rather than responders Ex. Sound when clicking on a link

Reduce Short-term Memory LoadRule of thumb: Humans can remember 7 +/-

2 chunks of informationDisplays kept simpleMultiple page displays should be consolidatedTraining if using codes, mnemonics, long

sequence of actionsOnline access to command-syntax,

abbreviations, codes, etc.

Prevent ErrorsLimit errors a user can

makeGray out menu items

that don’t applyNo characters in a

numeric fieldIn case of errors

Detect errorSimple, constructive,

and specific instructionsDo not change system

state

Prevent ErrorsError rate is typically higher than expected

What are common errors for us?Coding, typing, dialing, grammar

How can we design software to reduce them? Better error messages

Specific, positive, and constructive “Printer is off, please turn on” instead of “Illegal Operation”

Helps fix current errorHelps reduce similar errors Increases satisfaction

Reduce chance for errorOrganizing info, screens, menusCommands and menu choices should be distinctiveConsistency of actions (Yes/No order of buttons)

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Apply any five HCI principles to design the user interface for Academic Calendar and Event Planner for college. It should allow student to see any event organized by the department in the college. Students should register , view the venue and select the event. The report should be generated at the end of the event and will be passed to all faculties with attendance and event details. Assume suitable data and draw the interface.

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Case Study