P2

Perception

Colours

Luminance

Luminance is the measure of brightness of a point on a surface; it is indicator of how bright the surface will appear for example in a photograph. It is a photo metric measure of luminous intensity per unit area of light travelling in a given direction. Luminance is the amount of light that passes or is emitted from particular area that falls within a given angle.

Pop-out effect

When there are a lot of object and images that are next to each other, it will be hard to find out which one is more important. So by giving on of the object or images a brighter colour will make the object stand out more than the other objects. The human eyes will instantly pick up the differences in the objects, which are known as pop-out effect.

Trichromacy

Trichromacy is the condition of processing three different channels for taking in colour information. Creatures with Trichromacy are called trickchromats which we human are, because our retina contains three different types of colour receptors in our eyes. Human’s eyes see colour by using the three trichromatic systems but it can be hard when more than one trichromatic systems is being used.  

 Pattern

Proximity

Proximity is the sense that predicts how far away objects are from another object. In HCI proximity will show how close or how far an aspect of a design will be compared to another. For example on a sat navigation, the sat navigation will tell the driver how far he is from the exit.

Continuity

Continuity is a pattern that has been continued, for example a train line it has be continuity straight if the train line suddenly turn right the train will crash. Human can spot objects that are continuous more than non-continuous objects because it will take our brains more time to process.

Symmetry

Symmetry is the replica of an image that has been copied in a mirrored way. It is used to make the objects to look consistent and easy for people to, it also make the image more balanced. When designing a HCI by using symmetry it will make the HCI more users friendly.

Similarity

Similarity is a group of object that may be the same shape and size. Similar objects are used to create a pattern that work in harmony within the design

Common Groupings

Common grouping is a way that is used to separate different types of objects. For example we human will group couple of images and shapes together and the ones that stand out, we will be able to say that they don’t fit in.

Connectedness

Connectedness is object that connected using lines and other shapes such as circles. Humans’ minds can tell whether the two objects are connected or if they are separated.

Objects

Geon's

Geon’s are 2D and 3D shapes which include cylinders, rectangles, circles and other shapes. Geon’s can be 2D images that are easy to create and very easy to recognise and to be viewed by the human eye.

Gross 3D shapes

Gross 2D shapes that give the illusion of being 3D, the way how gross 3d shapes are done is by placing the object higher or lower than the original to give it the 3D effect. Some people have difficulties seeing 3D object due to some disabilities.

Predictive models

Reaction time

Reaction time is how long it takes the computer system to respond to the human input for pressing the keyboard or clicking on a program. Reaction time is counted in seconds, minutes or hours, so it can take a computer a couple of seconds from when keys are pressed to display on the screen.

KLM (keystroke level model)

Keystroke level model is the way of estimating how long it will take a computer system to complete a task using touchscreens, keyboards and mouse. Companies use KLM to improve their devices response time.

Throughput

Throughput show how fast application load up on it has been clicked on by the user. For example it will take 2 seconds to load up Google chrome once the user clicks on the icon.

Fitts Law

Fits law a model of human movement that is used in HCI.  Fits law describes amount of time that it takes a person to reach the computer input such as the keyboard, for example it can take me a second to move my hand from the mouse to the keyboard to input data.

Descriptive models

KAM (key action model)

KAM is the input devices like the keyboard that have many different function that can be categorised into 3 groups. Which are symbols, modifier and executive; some symbol keys can give graphics like letters, numbers and other symbols such as @ symbol.

Buxton three state models

The Buxton three state models concentrate on the dexterity in the way how the user makes movement using their input device such as mouse. Each input device needs to be very responsive and easy to use. The user of the input device should also be able to change some of the setting and preferences of the input device.

Guiard's model

Guiard’s model is the preferred method in how the user uses different input devices. For example some people are left handed, so the mouse and keyboard should be available for the left handed user to use. Some people may be disabled so they may not have their hands, so voice recognition can be used to input their data.

INFORMATION PROCESSING

Human as a component

Human as a component is that the computer is seen as human, so that people are able to interact with the computer. So the developers of the HCI will make sure that the HCI will meet the requirements of the people who will be using the HCI. This in turn will make sure that the interaction between the HCI and people will be correct.

Human information processing

Human information processing is a theory that says that humans process information a lot like computers. This is because the same as human a computer has brain, which is the CPU this controls every aspect of the computer the same as people brains. So when humans process information and understand it this is the same as computer take codes and processing them in to letters.

Goals, operators, methods and selection (GOMS)

GOMS is important in the development of a HCI this because this model allows the designer of the HCI to create the interface of the HCI.  So with GOMS, the goals are set (so what the system will do), the operators (so how the humans will use the system), the method (so how the goal will be reached) and selection the method the designer will chose for the HCI. GOMS helps how the interface of the system will be created and will be used by people.