1 / 14

425: HCI 1

425: HCI 1. DOET 4: Knowing What to Do. Today's Forecast. Lecture: DOET 4, Knowing What To Do Random surprise visits to zee Wheel of Pain * ... * (und Fear). Knowing What to Do. When encountering new objects, how do we know what to do? KITH

MartaAdara
Télécharger la présentation

425: HCI 1

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 425: HCI 1 • DOET 4: • Knowing What to Do

  2. Today's Forecast • Lecture: DOET 4, Knowing What To Do • Random surprise visits to zee Wheel of Pain* ... • * (und Fear)

  3. Knowing What to Do • When encountering new objects, how do we know what to do? • KITH • We've learned how to use a similar object. • We take a course to learn how to use it. • KITW • The object teaches us: instructions, labels, a manual, popup help, etc. • The design of the object can help us figure out what to do with it. • How? By intelligent/effective use of affordances and natural constraints. • Affordances - suggest range of possibilities of what to do • Constraints - limit the number of choices of what to do • put together a jigsaw puzzle • disassemble and reassemble a door lock for rekeying • build a spaceship out of legos

  4. Classification of Everyday Constraints • There are four main types of everyday constraints: • Physical • Semantic • Cultural • Logical Let's take a look at each of these.

  5. Physical Constraints • Physical constraints rely on physical reality to limit the user's set of possible physical actions. • To close a screwtop bottle, you must turn the cap clockwise; to open it, you must turn the cap counterclockwise. • To insert a key in a lock you must push the correct end into the keyhole. To open the lock, you must turn the key (counter)clockwise. • To open a door you must turn the doorknob, or raise/lower the handle. • Physical constraints work best (at helping us know what to do) when they are easy to see and interpret.

  6. Semantic Constraints • Semantic constraints rely on the meaning of a situation to limit the user's set of possible actions. • For a semantic constraint to work, the user (obviously) needs to understand the meaning of the situation and of the world in which it is embedded. • When an alarm sounds, the meaning of the situation drives one to act in a certain way (get alarmed; fight or flight!) and NOT to act in another way (sit down and relax). • Other examples ... ?

  7. Cultural Constraints • Cultural constraints rely upon cultural conventions to limit the user's set of possible actions. • Which side of the road to drive on • Which way to read a sign (page, etc.): left to right, right to left, top to bottom, bottom to top • How to type on a computer keyboard (Z location, diacriticals, etc.) • Guidelines for cultural behavior are stored as schemas. Schema: a memory-based knowledge structure that contains rules and instructions for interpreting situations and guiding behavior. • Other psychologists call schemas scripts or frames.

  8. Logical Constraints • Logical constraints rely on rational logic to limit the user's set of possible actions. • Logical contraints are what enables natural mappings to work. • A naturally mapped stovetop – one whose knobs clearly map to its burners – works not because of physical, semantic, or cultural constraints, but because of logic: the spatial relationship between controls (knobs) and targets (burners). • How do semantic constraints differ from logical constraints? • Examples ... ?

  9. ICE: Name that Constraint! • What types of constraints help us know what to do in these situations: Physical? Semantic? Cultural? Logical? (Hybrid?) • Stop at red traffic light; go at green. • Stand and bow to the Japanese executive you're having lunch with. • Fill your brake fluid reservoir. • Yield (or don't yield) to another car in traffic. • Communicate a work concern to your boss, not your boss's boss. • Change a bike tire (for the first time) without any instructions. • Don't make sudden movements if someone's pointing a gun at you. • Don't start eating dinner until an opening prayer has been said. • Choose D in a multiple-choice exam if A, B, and C are all wrong.

  10. Applying Affordances and Constraints to ETs • Applying well-designed affordances and constraints to everyday things can dramatically increase their usability. • Doors and light switches are good case studies. • All too often they are poorly designed (in terms of usability). • How about in this room? • Other examples of ETs that are often poorly designed ... ?

  11. Visibility and Feedback • Along with affordances and constraints, visibility and feedback also contribute a great deal to knowing – or not knowing – what to do with a device. • Memory jog: • Affordance: a property of a device that enables it to be used. • Constraint: a property of a device that limits its usage. • Visibility: the degree to which a device's intended use is visible (apparent) to the user. • Feedback: information a device communicates back to users about actions they have taken. (vid1, vid2, vid3)

  12. Making Visible the Invisible • Key parts of devices are sometimes invisible for aesthetic reasons. • Designers like to hide seams, cracks, handles, switches, etc. • But the usability of many of these devices would be dramatically improved by making these parts visible. • Has it ever taken you a full minute to find an on/off switch? • Without good visibility/feedback, users can run into problems: • Have trouble remembering their place in a sequence of steps • Have trouble remembering what needs to be done next • Have trouble checking info for correctness and changing it if necessary • A good visual display takes care of a lot of these problems. • When Norman wrote this book, visual displays were not as sophisticated or user friendly (high usability) as they are today.

  13. Using Sound for Visibility • When things cannot be made visually visible, designers should consider making them sonically visible. • It would be difficult to visually inform (quickly, efficiently, all at once) 1,000 people in a big building of the outbreak of a fire. • But a sonic alarm does the trick nicely. • Except for deaf people. • A fire alarm is an extreme example of sonic visibility; more subtle: • The click of a door bolt sliding into place. • The funny sound a car makes when something is mechanically awry. • The whistle of a tea kettle when the water's boiling. • The change in tone when a vacuum cleaner hose is clogged. • Cell phone ring tones. • Other examples ... ?

  14. Using Sound for Visibility • The use of sound for visibility is currently quite primitive. • Exceptions: • Some video games have very sophisticated sonic visibility. • Music as an aid to debugging complex program code. • Earcons - icons for the ear • Other examples ... ? • One big challenge with using sound for visibility: • Sounds, unlike visuals, extend beyond the user's border. • Unless the user is wearing headphones or has volume set very low, the sounds emanating from a device can be heard by anyone in earshot. • This can be very (very!) annoying and disruptive ... • Suggestions for how to get around this?

More Related