human computer interaction

HCI (Human Computer interaction)

Human computer interaction is important when it comes to program design, system designers need to keep the user in mind when designing a system.

There are two approaches to designing a system:-

* System approach – design the system and get the user to adapt to the system this is wrong as it causes stress to the user, and can be seen as unethical approach to system design, as you are not thinking about the user as a person, you are only thinking about the technology aspect as the design

This method is a bad idea, as the system wrongly designed may make people ill, two many bright colours can give someone a headache

* User approach – design the system with the user in mind and adapt the system to the user, as the user has to use the system after all.

The latter approach is the right way to design a system, a big buzz word when it comes to HCI is usability, can the user use the system or website you have designed.

Below are some quotes about usability:-

Janice (Ginny) Redish and Joseph Dumas, A Practical Guide to Usability Testing, 1999, p. 4

“Usability means that the people who use the product can do so quickly and easily to accomplish their own tasks. This definition rests on four points: (1) Usability means focusing on users; (2) people use products to be productive; (3) users are busy people trying to accomplish tasks; and (4) users decide when a product is easy to use.”

Using the 5Es to Understand Users by Whitney Quesenbery

“Usability starts with a philosophy – a belief in designing to meet user needs and to focus on creating an excellent user experience – but it is the specific process and methodology that produce the real goal of usability. A new usability process starts by looking at who uses a product, understanding their goals and needs, and selecting the right techniques to answer the question, “How well does this product meet the usability requirements of our users?”

Steve Krug, Don’t Make Me Think, 2000, p. 5

“After all, usability really just means that making sure that something works well: that a person of average (or even below average) ability and experience can use the thing – whether it’s a Web site, a fighter jet, or a revolving door – for its intended purpose without getting hopelessly frustrated.”

Jakob Nielsen, Usability Engineering, 1993, p. 26

“It is important to realize that usability is not a single, one-dimensional property of a user interface. Usability has multiple components and is traditionally associated with these five usability attributes: learn ability, efficiency, memo ability, errors, satisfaction.”

HCI and Usability was though about a lot in the design of the system here are some of the things that was used in the systems design

Navigation is important; the user must know where they are going in the system a good way of doing this is by Visual cues for example if you want your user to print something use a picture of a printer etc

In a report called “an interpretive study of visual cues in advertising” the author Professor Sandra Moriarty says this about visual cues, the context here is in advertising but it can easily apply to computer interface design, this report can be found at

“In order to understand how visuals signal meaning, we need to understand how symbolic meaning is produced.

The link between the signified and its signifiers is established through the process of cueing, but how meaning is signalled and the role of cueing in semiotic interpretation is less well understood. One of the early theorists, Charles S. Pierce, categorizes the type of signification as iconic, symbolic, or indexical and these categories are useful in framing a discussion of cueing. An iconic sign, for example, looks like what it represents–a picture of a rose, for example, has visual patterns and details that resemble a real life rose. Iconic signs are literal and representational. An indexical sign, in contrast, is a clue that links or connects things that occur simultaneously in nature. Wilted leaves, for example, may signal that a flower needs watering; smoke signals a fire.

A symbol, however, is more complex in terms of its cueing processes. A symbol is something that represents something else by convention or by association.

A cue, the signal that stimulates the production of meaning in a receiver’s mind, is particularly important in understanding symbolic meaning. At the symbolic level, the cue is more than just a simple representation because it elicits a complex structure of meaning based on previously encountered networks of associations”.

The system you are designing should also use the idea of memory cues such as all the back buttons are in the same place on all the screens so you know where they are to go back to the menu screen.

In the book Usability Engineering by Jakob Nielsen the author talks about computer systems having the sense of have memorability built into them in other words when you use a computer system you should able to remember where things are in the system because they are in the same place throughout the system.

Another thing to think about when it comes to HCI is what colours to use for example it would not be a good idea to use red or green as text colour otherwise people with colour blindness would not be able to see it, so green text on a red background is not a good idea, also on large screens it is a good idea to use a blue colour

Here’s what Christine Faulkner writes about the subject in the essence of human computer interaction

“At the periphery of colour vision, the eyes is lest sensitive to red, green and yellow light and most sensitive to blue light, for this reason, blue makes a good background colour, especially where the screen is large”


Professor Sandra Moriarty, An interpretive study of visual cues in advertising


Whitney Quesenbery, Using the 5Es to Understand Users


Janice (Ginny) Redish and Joseph Dumas, A Practical Guide to Usability Testing, 1999

Steve Krug (2000) Don’t Make Me Think!: A Common Sense Approach to Web Usability. New Riders

Jakob Nielsen (1993) Usability Engineering (The Morgan Kaufmann Series in Interactive Technologies. Academic Press

Christine Faulkner (1998) The essence of human computer interaction, prentice hall