The Law of Prägnanz is the tendency for all of us to interpret ambiguous images as simple and complete rather than as complex and incomplete. It is one of the key principles underlying Gestalt psychology and is also sometimes known as the law of good configuration, law of simplicity, law of pregnance, law of precision or law of good figure. Read more »
Easy user experiences
Mapping is the term used to describe the relationship between controls and their movements or effects, and good mapping is an important part of making the user experience easy and enjoyable. For example, the Segway human transporter goes forward when the user leans forward and back when the user leans back. A great use of mapping. Read more »
Different scale, same pattern
Self-similarity is a common property in nature, usually seen as intrinsically aesthetic, by which a form is made up of parts similar to the whole (or to one another). Natural forms are highly likely to to exhibit self-similarity at many levels of scale, in contrast to human made forms which usually do not. An aerial view of a coastline reveals the same basic edge patterns whether you stand at the water’s edge or view from a helicopter above (or even higher), in the same way that the Mandlebrot fractal set above, with the same pattern at varying levels of detail. The whole is a mosaic of smaller wholes, on and on into infinity. Read more »
Tip of the tongue
Our ability to recognise things that we have previously experienced is much better than our ability to recall the same things from memory. Recognition is much easier because recognition provides cues which helps us sort through our vast memory and find the most relevant information. We all find multiple choice questions easier than short answer questions, because the list of possible answers makes it easier and quicker to find the right one, as we can narrow down options very efficiently unlike short answer questions which leave a much greater range of possibilities for us to search. Read more »
The ratio of nature
The golden ratio is the ratio between the elements of a form such that the sum of two elements are in the same ratio to the larger one, as are the larger and smaller elements to each other (see the rectangle below). This ratio approximates 1.618 (or 0.618; the two numbers are the reciprocals of each other) and is found throughout nature (for example in many seashells), art, architecture and also in the dimensions of the human body. It is also called the golden mean, golden number, golden section, golden proportion and divine proportion, and is closely linked to the Fibonacci Sequence (read more here) as the ratio of numbers in this sequence converges on the golden ratio.
Tired of too much choice?
In the last post I wrote about the effects of decision fatigue, and its bad effect on the quality of decisions that we make in life. Hick’s Law is a common principle of design, and is the design consequence that the time it takes to make a decision increases as the number of alternatives increase (a common sight in today’s retail landscape). The law itself is used to estimate the time it will take someone to make a decision when presented with multiple options. Although this has everyday consequences, outlined clearly and sympathetically in Barry Schwartz’s The Paradox of Choice, it also has very serious consequences in emergency situations. For example, when a pilot has to press a particular button in response to an event, then the decision to select the correct button will take longer when there are more options. Read more »
The sequence of nature
A Fibonacci sequence is a sequence of numbers in which each number is the sum of the two preceding numbers – for example, 1, 1, 2, 3, 5, 8, 13, etc. Patterns which reflect this sequence are commonly found in nature, for example the petals of flowers, spirals of galaxies and bones of the human hand. Read more »
A tidy mind
For those overwhelmed by information or data (a common problem in business intelligence), it always helps to sort your information in order to make better sense of what you have. According to the design principle of ‘Five Hat Racks’, there are five ways to organise information: by category, time, location, alphabet and continuum*. [*Continuum is sometimes renamed hierarchy, providing the simple acronym of LATCH.] Read more »
“Attractive things work better … When you wash and wax a car, it drives better, doesn’t it? Or at least feels like it does.” - Donald Norman Read more »
The 80/20 Rule is also known as Pareto’s Principle or sometimes “the vital few and trivial many”. Vilfredo Pareto was an economist who studied the distribution of income at the start of the 20th century, observing that 80% of land in Italy was owned by 20% of the population. In design this implies that a high percentage of effects in any system are caused by a low percentage of variables. The effect is observed in all systems, natural or artificial, and is the most basic case of a power law such as the Zipfian distribution (the distribution of words in a language). Earlier today I watched a TED presentation on the search for planets outside our solar system – now that technology has improved such that we are able to find smaller planets, the distribution of the size of the planets followed a beautiful power curve (you can see an example below). The power curve is also the basis of Chris Anderson’s Long Tail, although his long tail focuses on the trivial many (which he argues are not trivial when modern connectivity and distribution make them easy to access).