Human Computer Interaction

• Human capabilities are influenced by emotion.
• There are two stages in vision: physical reception of stimulus and processing and interpretation of stimulus.
• The eye is a mechanism for receiving light and transforming it into electrical energy.
• The retina contains rods for low light vision and cones for colour vision.
• Ganglion cells in the brain detect pattern and movement.
• Visual angle indicates how much of a view object occupies and relates to size and distance from eye.
• Visual acuity is the ability to perceive detail, which is limited.
• Familiar objects are perceived as constant size, regardless of changes in visual angle when far away.
• Overlapping cues help perception of size and depth.
• Brightness is a subjective reaction to levels of light, which is affected by the luminance of the object and measured by just noticeable difference.
• Colour/Color is made up of hue, intensity, saturation and cones are sensitive to colour wavelengths.
• Individual differences in emotion can be long term, such as sex, physical, and intellectual abilities, or short term, due to the effect of stress or fatigue.
• Various theories of how emotion works include James-Lange, Cannon, and Schacter-Singer.
• Negative affect can make it harder to do even easy tasks, while positive affect can make it easier to do difficult tasks, according to Donald Norman.
• Aesthetically pleasing and rewarding interfaces will increase positive affect.
• Stress will increase the difficulty of problem solving for users, while relaxed users will be more forgiving of shortcomings in design.
• Emotion also involves changing individual differences, such as age.
• Affect influences how we respond to situations, with positive affect leading to creative problem solving and negative affect leading to narrow thinking.
• Understanding the context in psychology and particular experimental conditions is generally required for correct application.
• Psychology has some direct applications, such as understanding blue acuity and its implications for design.
• Emotion clearly involves both cognitive and physical responses to stimuli.
• Design decisions should not exclude a section of the user population.
• The biological response to physical stimuli is called affect.
• The visual system compensates for movement and changes in luminance.
• Context is used to resolve ambiguity.
• Skill acquisition is a skilled activity characterized by chunking, where a lot of information is chunked to optimize Short Term Memory (STM).
• Information gives knowledge that it has been seen before, which is less complex than recall.
• Mental models are created by humans to explain behaviour.
• Information is a cue.
• Deductive reasoning can lead to logical conclusions that are not necessarily true, for example, "If a card has a vowel on one side it has an even number on the other".
• Problem solving is the process of finding a solution to an unfamiliar task using knowledge.
• Deductive reasoning involves deriving logically necessary conclusions from given premises, such as "If it is Friday then she will go to work" and "If it is raining then the ground is dry".
• Problem space theory suggests that the problem space comprises problem states and problem solving involves generating states using legal operators.
• Abductive reasoning involves reasoning from event to cause, such as "Sam drives fast when drunk".
• Analogy involves analogical mapping, which is the use of knowledge from a similar problem in a different domain.
• Optical illusions sometimes occur due to over compensation.
• Inductive reasoning can be unreliable as it can only prove false not true, but it is useful.
• Errors can be slips, which are right intentions but failed to do it right, or mistakes, which are wrong intentions.
• Inductive reasoning involves generalizing from cases seen to cases unseen, such as "all elephants we have seen have trunks" and "all babies cry".
• Abductive reasoning can lead to false explanations and is unreliable.