P2

Perception

Colours

Luminance- is a measure of brightness of a point on a surface. Luminance is an indicator of how bright the surface will appear. Luminance is a photo metric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through or is emitted from a particular area and falls within a given angle. 

Pop-out effect- when we have a bucnh of objects, images etc. next to each other or placed on a piece of paper, it would be quite hard for us to distinguish them as something more important than the other one. By giving one of few objects a brighter color we are making them stand out from the other more dull images. Our eyes can immeadiately tell that this images is different from others and this is what a pop-out effects is. 

Trichromacy- is a condition of processing three different channels for conveying color information. Organisms with trickchromacy are called trickchromats. Humans are trickchromats and their retina contains three different types of color receptors. Our eyes detecet colors using these 3 trichromatic systems but they can be tricked that more than one color has been used.  



Pattern

Proximity- is a sense of how far aways objects are from one another. In HCI design proximity could mean how close or far away certain aspects of the design are to one another. Objects that are equal distances from one another can be viewed more easily than objects that are placed at different distances. For example all iphone apps have the same amount of space between eachother. 

Continuity- is a pattern that is being continued. For example a straight light has a continuity of being straight, if a line suddenly goes up or down it brakes the pattern and is no longer continious. Humans can easier spot continious objects or objects than non continious objects as they take more time to be processed by our brain. 

Symmetry- is an exact replica of an image that is only copied in a mirrored way. Symmetry is used to make the objects look consistent and easier to see by people and to balance out the design and layout of your device or software. Symmetry is very important and must be taken into consideration when designing a user friendly enviroment.

Similarity-  is a group of objects that may have the same size, shape or other features. Similar objects are used to create a pattern and a sence of harmony in the design. For example all windows or iphone apps are the same size and shape. They all are considered simialar even though they may have different colors and names.

Common Groupings- is a way of seperating different types of objects. For example we have a bunch of squares which are either blue or red, what common grouping does is seperate all squares into two groups: red squares and blue squares. This way we wouldn't just have a bunch of squares which would be hard to see and calculated, what we would have is a group with blue and a group with red squares.

Connectedness- are objects that are connected using lines or other shapes. Our mind can easily tell whether the two objects are connected or if they are seperate. 



Objects

Geon's- are simple 2D or 3D shapes that include cylinders, rectangles, circles, bricks and other. Geon's can also be thouht as simple 2D images that are easy to create and very easiliy recognised and viewed by human eye. 

Gross 3D shapes- are nothing more than 2D shapes that give out an illusion of being 3D. A copy of an object is placed slighty higher or lower to the original to make it look 3D. Some people have some difficutlies seeing 3D objects. 





Behavior Models


Predictive Models

Reaction time- is how fast the computer responds to human inputs e.g. moving mouse, pressing keyboard or mouse buttons. For example reaction time could be counted in seconds or minutes, it would not even take one second for a computer to respond to your press of a button.

KLM (keystroke level model)- is a way of estimating how long it will take for a computer to complete simple data entry tasks using keyboards, mouses or touchscreens. Companies use this to improve their current devices and their response time. 

Throughput- is how fast the application loads once it is clicked on by a person. For example it takes about once second for an app on an iPhone to launch once it is pressed on. 

Fitts Law- is a model of human movement used in HCI. It basically describes the time it takes for a person to reach its input destination like keyboard or mouse. For example it could take me two seconds for me to move my hand from the keyboard to the mouse. 



Descriptive Models


KAM (key action model)- input devices like keyboards have many different buttons which can be categorized into 3 groups: symbol, modifier and executive. Symbol keys give you graphics like letters(a,s,d), numbers (1,2,3) and other symbols (:,@,{). 

Buxton three state model- this model focuses on the dexterity in which user make the movement using their input devices. Every input device needs to be very responsive, easy and freely to use. Users should also be able to change some settings and preferences like mouse sensitivity. 

Guiard's model- realtes to the preffered method of using different input devices. For example some people are left or right handed, so mouses and keyboards should be available for both. Some people do not have any hands so technology like voice recognition is used in these cases. 





Information Processing

Human as component- when designing complicated HCI, the moist important thing to take into consideration is human, as we will be the ones to use the device or software. All HCI are designed specifically to meet human needs. For example keyboard was designed for our fingers and hands. When creating new technology people need to think about how people will use it and how it will be accessible for people with disabilities. 

HIP (human information processing)- is about a theory which states that humans work a lot like computers. People think that our hands, ears and other senses and body parts are just like the input devices of a computer. Human brain is just like a CPU in a computer. People always wondered if computers are smarter than them but it is certain that they are less lazy :D .

GOMS- stands for goals, operators, methods and selection. This model is used to see what and how the tasks are undertaken by the HCI they are creating. Goals refers to what the user wants to do on the device or software. Operators are the steps and movements that will be needed to complete the goal. Methods are the other ways/ alternatives a user can use to accomplish his goal. Selections are the easiest and fastest ways of accomplishing your goals. For example instead of going through a long process of saving a file you could use a keyboard shortcut instead.