HCI P2

HCI P2

Perception 

Perception is basically how we view things and how we interpret it. A good example of this is Optical Illusions; The picture of the Rabbit or Duck is a good image as from the left it is a duck and from the right it is a rabbit but some people may either see none, or just one of the two. Things like this can effect a designer when creating e.g a website or a 3D model as you must be aware of the client’s requirements for how things must look e.g. They may have dyslexia. But on the other hand, the client may not be the user and they may not think to look into these things or disregard them completely. 

Colour

Colour is something that is very important and the designer will need to consider this when they are designing the GUI. Yellow background colours can be less appealing but can be very helpful to others that suffer with migraines or dyslexia. Plain colours (grey, light blue) are generally used because they cause less interference with people’s sight but colours on the (windows) desktop now can be changed accordingly.
Another part is text colour. Some text can look very harsh and difficult to read on certain background colours and for somebody with colour blindness it could be impossible to read if there are certain combinations.

 You will notice GUI's that people look at for a long time tend to be gray, boring colours, but this is for people that look at them for extended periods of time. If you looked at yellow for a long time you will soon start to get a head ache. The dull colours prevent this and designers have thought about this and make it according. Another thing is text, some desginers will put a colour text onto of a symilar background, but this causes the text to get lost in the background. Developers should think about this and cater it to everyone, not just people that can differentiate between dark yellow and light yellow.

This chart shows exactly that, as you can see, some colours are quite hard to read over other colours and some are harsh on the eyes. This chart should make it easy to select the colour that is right for the developers GUI.

Luminance 

There are 3 colours in the trichromatic system that are identified by 3 cells in the retina of your eyes. People believe that receptors in your eye take signals and then these signals form red-green, yellow-blue and black-white. These signals are called opponent colour channels as they send opposite colours.

Pop-out Effect
When there are numerous symbols and images aligning, colouring and adjusting them differently can make these images stand out from other ones. Making the images, text stand out is furthermore known as a pop out effect. Our eyes notice hues using the 3 trichromatic schemes, but we can be deceived into conceiving that more than one colour have been utilised. When conceiving GUI which is to be utilised at night or in poor lighting then luminance might have to be essential.

Pattern

Patterns are referred to as templates, but a user of the GUI would think it was a picture. An example is the template used for dialogue boxes in Microsoft. The Gestalt laws are used for pattern perception and form the rules for designs. 

Ø  Proximity
 Items we see that are grouped close together. 

Ø  Continuity 
Straight lines that don't stop are better to read than different shaped varied lines. 

Ø  Symmetry
Symmetrical shaped are easier to see than irregular shapes.

Ø  Similarity
We see objects that are the same as a group. Objects that look different will usually be viewed as an individual object.

Ø  Fate
 We see items that move together as a group.

Ø  Region
we can see items that are close together as a group.

Ø  Connected:
We see items that are connected by continuous lines as linked to each other. 

Predictive models
Predictive models are utilised to predict how humans will interact with interfaces once it is made and available to the public. Reaction time is the time that it takes to answer to an interface – for example, how long will it take for a user to come to the mouse and click on an icon. The form for this is the KLM (Key-stroke grade Model). The Through-put is the time that it takes for the demand to be performed. For demonstration, in up to date expertise, the quicker the processor is the better the throughput. Fitts’ law is alike to KLM – the time it takes your arm to come to the device is determined by Fitts’ Law. 

Descriptive Models

These models describe how certain parts of technology work. The Key-Action model details what the functions of each key of technology is. For example on a keyboard, each key has a different use and function. There are certain things that are set before it is sent out for public use. Things like ctrl+C will have already been set. The Buxton’s Free State form (BTS) works out what kind of input methods can be utilized while conceiving the interface. It should be kept in mind how users may desire to interact and should have all the options open for them. 

Information Processing 

Information Processing is how information is processed. It can also be how it will be processed and how quick it is going to be processed. 

Humans as a component 

Humans are the most important things to consider in HCI design. Its is often hard to find out peoples needs and expectations. One way to work this out is to do a risk assessment to work out what is needed. 

Human Information Processing
Human Information Processing is the way is which our body and brain takes the information and processes it.