Scientific Underpinnings of Usability EngineeringObjectivesDesigning StuffTwo weeks ago . . .Human Information ProcessingEye PhysiologyEye MusclesVisual FieldRetinal PhysiologyDistribution of Rods and ConesVisual SensitivityVisible SpectrumNeural PathwaysAftereffectAmbiguous FigureSensation/PerceptionPerceptual Psy – Color VisionPerceptual Psy -- DepthMore Depth CuesMonocular Cues -- InterpositionMonocular Cues -- SizeSlide 22Slide 23Monocular Cues – Linear PerspectiveMonocular Cues – Texture GradientSooooo . . .Monocular Cues – Aerial PerspectiveMonocular Cues -- ShadingMonocular Cues – Motion ParallaxMore visual perceptionPonzo IllusionMuller-Lyer IllusionPsycholinguisticsThe Psychology of ReadingSome facts about readingMore factsIconic MemoryIconic Memory (cont’d.)How do you know, Randolph?Rubenstein et al. (1971)More DataThe PointIn week 1, we were talking about Perception and CognitionSlide 44Experiment 1Slide 46Slide 47Experiment 2Slide 49Slide 50Experiment 3Slide 52Slide 53So?SO WHAT?Last week’s homeworkComing UpR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] Underpinnings of Usability Engineering February 16, 2006R. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] this class you will be able to (it is my hope!):•Describe some eye physiology•Explain how the visual system works (somewhat)•Identify visual cues to depth•Explain some aspects of the psychology of reading•Explain how perceptual and cognitive psychology influence HCI designs•Have an excellent memory for “VAM”•Discuss the importance of designing systems to match the human.R. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] Stuff•In Week 1, I asked the question “What would a system look like if we were designing it for dogs?”–Wouldn’t be a lot of text.–Wouldn’t require a lot of dexterity.–Might code information in smells and tastes.•But we’re designing systems for humans (usually!). So it will behoove us to know something about how human beings take in and process information.R. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] weeks ago . . .•Why were those designs poor?•At a high level, because they didn’t match your understanding, your organization of information. (Your mental model.)•The whole point: Let’s design systems to fit people instead of the other way around.R. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] Information Processing•How do human beings take in and process information?–Sensory psychology – how humans transform physical energy (e.g., light and sound waves) into sensory signals to and in the brain.–Perceptual psychology – how humans interpret these sensory signals as perceptions.–Cognitive psychology – how humans think about these perceptions, and previous experiences, and their own mental creations, and . . . –Psycholinguistics – The psychology of language -- what goes on between the time I have a thought and you have the same (or similar!) thought, whether I say it or write it.R. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] PhysiologyR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] MusclesR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] FieldR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] PhysiologyR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] of Rods and ConesR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] SensitivityR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] SpectrumR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] PathwaysR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected]. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] FigureR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected]/Perception•POINT: Perceptions are made up of more than just a collection of sensations!•OTHER things influence our perceptions, e.g.,–Our experiences–Our biases–The context–Our current emotional state–Etc.•So, what does that have to say about designing human-computer interfaces???R. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] Psy – Color Vision•Color perception – 3 types of cones (RGB)R. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] Psy -- Depth•Different visual cues to depth–Oculomotor vs. Visual•Oculomotor – Lens accommodation and extraocular muscle convergence are “read” by the brain•Visual: Binocular vs. Monocular–Binocular – Stereopsis (retinal disparity)–Monocular (next screen)»Static»Motion parallaxR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] Depth Cues•Monocular–Static•Interposition•Size•Perspective–Linear perspective–Texture gradient–Aerial perspective–Shading–Motion parallaxR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] Cues -- InterpositionR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] Cues -- SizeR. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected]. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected]. G. Bias | School of Information | SZB 562BB | Phone: 512 471 7046 | [email protected] Cues – Linear PerspectiveR. G. Bias |