Usabilla UX Index – Kano, Occam, Gestalt and more…
The ABC of Usability has resurfaced, although you may notice a few changes. Now known as UX Index, the concept is still the same and we’ve provided five fresh new phrases to learn. Each month we will continue to add five words to our existing collection of Usability and UX definitions which we hope you’ll find both interesting and useful.
So here are November 2014s five words:
The Kano model is a theory created by Noriako Kano in the 1980s for designers to have a simple way of prioritising features when developing products. This theory allows designers to analyse their customer’s needs and desires by classifying features of products into 5 sections, resulting in products that meet basic needs but are still innovative.
These five sections are:
Must have features – capabilities that a user expects from the product and often take for granted. If the product fails to hold these features it is basically incomplete. Therefore users would be frustrated if these features were non existent yet when they work well users are neutral e.g. car doors
One dimensional features – are received differently depending on how well they are implemented. Users will be excited if these features are implemented well and disappointed if they are not
Attractive features – are unexpected features so users will be excited if they are present and work well but not disappointed if they are absent
Indifferent features – neither excite or disappoint users
Reverse features – their reception depends on the user and their needs. Some users will be excited and others disappointed by their presence
The model works by asking users a question to which they can reply with one of five answers.
Question: ‘If your car has no doors how do you feel?”
Answers: 1. I like it that way 2. I expect it to be that way 3. I am neutral
4.I can live with it that way 5.I dislike it that way
These answers can be put into a graph to make it simple for designers to see how individual features will be received. Prioritising features usually works in the order of the five sections from must have to reverse.
In any composition there are elements that attract more attention than others. The more prominent the image the higher it’s visual weight. Key sections of a composition usually need to be visually heavier than the other images so that users are guided to the areas of primary importance. Each decision you make about the appearance of a word or image has an impact on the overall flow of the page, including even minor details such as the space between letters (kerning).
The visual weight of an image can be adjusted in value by colour, contrast, size, position, density , saturation, depth of field and complexity. By distributing the weight of each element of a design it creates a visual hierarchy that provides users with a clear idea of what order to view them in.
Occam’s/ Ockham’s Razor
A problem solving principle which argues that simplicity is better than complexity. Named after 14th-century logician and theologian William of Ockham this theory has been around a while and used in many different industries. In design, Occam’s Razor encourages us to eliminate unnecessary elements that would decrease a design’s efficiency. So when two products or designs have the same function, Ockham recommends the simplest should be selected. Therefore when evaluating your designs, analyse each element and remove as many as possible without compromising the overall function. This should ensure that you remain with elements that are minimised as much as possible without compromising their function
A great introduction into Ockham’s razor can be found at Web Designer Depot
Gestalts Laws of Grouping
Gestalt is a psychological term meaning ‘global/unified whole’ and the term refers to theories of visual perception generated in the 1920s by German psychologists who believed that the whole is greater than some of it’s parts. It describes how humans perceive patterns in objects. There are 4 principles or laws – similarity, proximity, continuity and common fate.
Similarity – grouping similar images together
Proximity – grouping objects which are near to each other
Continuity – when objects that intersect are viewed as one object
Closure – when images are arranged to form an incomplete shape but are still perceived to resemble the full shape.
To develop your understanding of Gestalt’s Principles this is a useful interactive diagram
A cyclical process of developing interactive prototypes for users and stakeholders to test. Rapid prototyping is a quick way to produce functional web applications and products, improving communication, decreasing development time and minimising engineering due to mistakes being spotted early in the design process. Once the first mistakes are spotted, they are improved and tested again until the developers are confident it is ready.