Johnson, J. (2014). Designing with the mind in mind: simple guide to understanding user interface design guidelines (2nd ed.). Boston: Elsevier.
--Johnson begins this chapter by outlining the biasing factors of The Past (our experience); The Present (the current context); and The Future (our goals). He then proposes the Idea of perceptual priming where in we can be influenced giving the example of
“You are meeting with a real estate manager. Discussing plans for a new campus of company buildings. The campus consists of a row of five buildings, the last two with T-shaped courtyards providing light for the cafeteria and fitness center. If the real estate manager showed you the map in Figure 1.1, you would see five black shapes representing the buildings” (Jonson, 2014, p.1)
This context in the present primes the audience’s mind to see building shapes, however, if the image was primed as a billboard that reads “Life” then the white areas begin to clearly register as text. A similar scenario can occur with shapes known as pareidolia, since our brains have evolved to be able to recognise human faces, we sometimes see them in places where none exist, for instance in 1976 the Viking 1, prior to landing on Mars took Images from orbit. One of which (shown below on the left) became known as the as the “Face on Mars”, however in 2001 NASA concluded the primary mission of Mars Global Surveyor (MGS) project which captured a higher resolution image of the area, showing the face to have been an optical illusion brought on by circumstantial lighting.
--We are also influenced by familiar patterns; our past experience of these patterns influences our behaviours when we are experiencing a similar scenario. An example provided by Johnson is the following image, this shows an example within UI design were user’s past experience makes them take for granted the location of the “Next” button.
--Johnson describes habitation as another influence on our perceptions where in recurring exposure to the same perceptions reduces our sensitivity to them. He states that this occurs on a neural level where our minds begin to ignore repetitious elements of the world.
“We experience habituation in computer usage when the same error messages or “Are you sure?” confirmation messages appear again and again. People initially notice them and perhaps respond, but eventually click them closed reflexively without bothering to read them.” (Johnson, 2014, p. 5)
By this fact using reedition can be beneficial to the user in addition to being disadvantageous in other situations. The reflexive knowledge of the UI assists in navigation of consistent menu elements, however notifications placed in the same location and used too frequently would cease to be notifying.
--Attentional blink is a phenomenon referenced by Johnson where recognition of a stimuli with multiple stimuli quickly succeeding each other impedes our ability to recognise the next set of stimuli.
“For a very brief period following the recognition— between 0.15 and 0.45 second— we are nearly deaf and blind to other visual stimuli, even though our ears and eyes stay functional.” (Johnson, 2014, p. 5)
A good example may be the Marvel logo stings that play in the Disney Marvel Movies.
--In explaining how perception is bias, Johnson discusses how it is influenced by current context. To example this he uses optical illusions to demonstrate how what we understand of what we see is predicated on its surroundings especially when the image is obscured in some manner, for this he uses the Muller-Lyer illusion (figure 1.6) when two lines of equal length appear to be different lengths due to the fins or arrows at the end.
--However, this example only demonstrated bias from a visual context, however perceptual bias can occur across the senses with each sense potential biasing the others. Johnson quotes the McGurk Effect wherein a video of someone saying “bah, bah, bah” then “dah, dah, dah”, then “vah, vah, vah” the viewer will hear the syllable indicated by the speaker’s lip movements rather than the audio. This is similar how in ventriloquism we are tricked that the dummy is speaking. (Johnson, 2014). Furthermore, we have our perception biased by our goals biased by our goals. The goals specified by Johnson are
“Guide our perceptual apparatus, so we sample what we need from the world around us. Filter our perceptions: things unrelated to our goals tend to be filtered out preconsciously, never registering in our conscious minds.
For example, when people navigate through software or a Web site, seeking information or a specific function, they don’t read carefully. They scan screens quickly and superficially for items that seem related to their goal. They don’t simply ignore items unrelated to their goals; they often don’t even notice them.” (Johnson, 2014, p. 9)
Johnson is saying that users will seek solely for the object of their query and become perceptually blind to any unrelated result. He states that this behaviour is influenced by age as adults become more goal oriented where as children are less goal orientated than adults making them more likely to observe more but be more easily distracted. (Johnson, 2014)
In order to avoid perception bias, he proposes three solutions.
Design In Context
Daniel Thomas Coates, graphic designer based in the UK. Currently a student at the University of Cumbria, Carlisle.