This morning, I got up from my desk and walked towards the watercooler to fill up my glass. I walked about halfway to the kitchen before realising I forgot my glass – the glass I intended to fill up, pretty much the reason I got up from my desk in the first place.
Incidents like this are far from uncommon. Other examples you might have experienced are walking into a room to realise you have no idea what you are doing there. Or putting orange juice in your cereal instead of the glass next to it. We’re humans and this is how our brains work. Knowing about this fact of life certainly helps designers of all specialties create better products or interfaces that are intuitive to use, often times simply because they’ve taken into account our flaws, should we concede to call them that.
The psychology of performing tasks
These things happen because the brain can get sloppy from time to time. Our days consist of performing tasks of different kinds and varying motivation – some new and exciting, others dreadfully repetitive. To perform a task we go through a series of steps: we form a goal, plan the action, perform the action and evaluate the outcome. Not all actions require such careful planning and examination. Some things we do almost subconsciously, and sometimes our busy brains decide to take some shortcuts, like when our biases are hard at work (archived) without us even noticing them. Let’s have a look some examples of slips and mistakes, and how designers can work to avoid them.
Designing interfaces that prevent errors
Designers should know that the brain can’t be trusted. It is not without reason ATM’s return your card before the cash you are withdrawing – getting money is the goal, so without this detail, you would most likely walk away without your card every other time.
Truth is, if it is possible to make a mistake, someone will make it. Digital designers should aim to prevent user errors as far as possible, and if an error is made the consequences should be minimised and a solution should be easy to find. Businesses could assess how well their current websites are doing the job they’ve envisioned the website should do and consider whether redesigning the website would correct some issues or improve the user experience.
People make slips and mistakes for different reasons. Mistakes can be made if two tasks start off similarly, and then divert – especially if one is performed more frequently than the others. When playing card, for example, you have to remember that the sequence of numbers changes after 10 and continues jack, queen, king. To minimise slips designers should avoid using similar patterns to then diverge – it might confuse two activities and are hard to keep track of.
The ‘juice-in-cereal’ example mentioned earlier, illustrates a description of a target which is too vague. It was not specified that juice should go into the glass, so the brain assumed that a round container, the bowl, would work just as well. The result is performing the right action, but with the wrong objects. When designing interfaces, designers should make sure different actions are not all represented in the same way – the more options presented, the harder it will be to differentiate.
When I forgot to bring my glass to the kitchen this morning, I experienced a memory slip. Pesky memory slips can cause all kinds of errors – missing steps in a planned action, repeating certain steps or simply forgetting the goal. It is hard to avoid these kinds of errors in user interfaces because limitations and interruptions often come from outside the system. However, a good rule of thumb is to design for a process that can be continued after an interruption without blaming the user. Errors can be discovered by feedback and confirmation of choices – even better if a solution is offered, and actions are reversible. Especially when building custom software.
TLDR: Everyone messes up, don’t make it painful! Empathy is the new black.
Further reading: The Design of Everyday Things by Don Norman.