HCI Principles - Behaviour Models

Behaviour Models

Behaviour Models are there to help the creator test how the GUI in functioning (How efficiently it is running and how easily it will be able to perform tasks).

Behaviour Models can be divided into two categories which are:

Predictive Models -  Keystroke Level Model and Fitts’ Law

Keystroke Level Model – Keystroke Level Model is used to determine the amount of time it takes the user to interact with the Graphical User interface. For example it will determine how long it takes the user to complete tasks within the interface such as how much time it will take to interact with a button on the keyboard or how long it will take the user to point at a specific part of the interface with the mouse icon.

Fitts’ Law -  Fitts’ law is a model used to determine what size the creator should make certain parts of the interface such as desktop icons and menu’s within the interface. It basically states that the bigger the area that the user wants to interact with the less time it will take to interact with this given area. For example the creator should make the start menu button on the desktop quite large in size compared to the other icons surrounding it therefore making it stand out and will make reduce the time it will take for the user to interact with it by using the mouse pointer.

HCI Principles - Perception

 

Perception

When it comes to designing a GUI (graphical user interface) perception is a very important factor. Perception is all about how someone using a GUI views and recognises certain aspects of the interface. When it comes to designing a GUI perception is involved in a manner of different things such as Positioning of windows, colours and the positions of icons on the desktop. All of these things will have an effect on what way a user of your interface will view and interact with it.

When someone is designing a Graphical User Interface they need to take into account the needs of the people that are going to be using it on a daily basis as the person who is designing it may not be associated with the same group of people that are going to be interacting with it. For example if I was designing a GUI I would have to take into consideration that people with disabilities may be using it therefore I would have to:

• Use a fitting colour scheme for people with eyesight problems. (Change colour of background, text and Window colour)
• Use a suitable size of icon for desktop shortcuts.
• Never put text on a background that will clash as this could irritate the users eyes and make the text appear blurry.

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