The Gestalt principles of visual perception describe how our brains make sense of what we see. For example, they explain how we associate a photo with the text of a newspaper article or understand a series of words as a sentence on a billboard. These principles originated from the field of Gestalt psychology in the early twentieth century.

In laying out sketches, I try to consider how a viewer will understand what connects with what, the order in which the viewer will read the sketch with their eye, and how colour or formatting link related elements—skim through the back catalogue to see it in action. In creating each sketch, consciously and unconsciously, I use many of the standard Gestalt principles of design.

There are many Gestalt principles and some variations in the names. I chose seven common principles to illustrate:

Proximity
Objects that are close together are perceived as a group

Similarity
Similar objects are perceived as a group

Continuity
Elements on a line or curve are related

Closure
Completing missing parts of images to create a whole

Figure-Ground
Identifying what's in the foreground or background

Symmetry & Order
Perceiving symmetrical or orderly elements as a group

Common Fate
Objects moving together are perceived as part of a group

The Gestalt principles are helpful for information design, user interface design, user experience design, graphic design and just about any design. It is also fascinating to spot how you unconsciously use them when interpreting designs you see. For example, look at the signs in an airport, a menu, or a page of your favourite app and see which principles are in play.

The Interaction Design Foundation has a great article on the Gestalt principles that explains their use in design in more depth. You'll also find many others.

Gestalt principles

The isolation effect is our tendency to remember an item that stands out in some way from a set of otherwise similar items—you might easily guess, for example, which name we are more likely to remember from a list of Tom, Terry, Angelica, Theo and Tyler.

When presenting information, the isolation effect is practical if you wish to draw attention to specific items. By standardising the presentation of other items in a list, maybe by muting the colours, making them the same size, or removing features that stand out, you can draw people's attention and improve people's memory of your chosen items.

The isolation effect is standard in web design by using distinctiveness: red notification bubbles on a set of otherwise homogenous apps, a "most popular" plan more prominent than the other options, or a Call-To-Action (CTA) button in a contrasting colour.

The isolation effect is also known as the Von Restorff effect after the German psychiatrist Hedwig von Restorff. See, for example, Hunt, R.R. The subtlety of distinctiveness: What von Restorff really did. Psychonomic Bulletin & Review 2, 105–112 (1995) for a summary of Von Restorff's most cited paper on the effect.

The isolation effect

Confirmation bias is the big one. The bias that leads us to live in a world of our own choosing, finding the information that already fits with our beliefs and ignoring or discounting what doesn't. It's the bias that makes two sides get further apart rather than closer together.

Edward De Bono in Water Logic suggested a metaphor for thought as channels of water. As water runs through the channels the channels get deeper, and as they get deeper it pulls more of the water into the main channels until there is only one way. Confirmation bias can act like that.

It's important to work to understand different opinions, not discount them upfront. To use our empathy to understand why others feel the way they do. And when we deliberately seek out information that challenges our point of view we will usually find a richer, more nuanced world that helps build bridges with others rather than drive us apart.

Confirmation bias

I hadn’t given much thought to hope, beyond it being a nice feeling to have, until I heard of CR Snyder’s cognitive model for hope which shed a new light on it for me. He proposed a model of hope where (paraphrasing) an individual may be hopeful if they have:

Goals they desire. If you don’t or can’t picture any future state you’d like then you won’t have a lot of hope.

Pathways. You need to see some ways that you may make step-by-step progress towards a goal.

Willpower or agency. You need to be motivated and believe that you have the ability to succeed at your goal.

With all of these you can imagine feeling hopeful. Without any one of them and you probably won’t so much.

The mountain is the Ogre, a wholly impossible looking peak scaled by Doug Scott and others for which I would have had zero hope to climb (no pathways, no willpower) and yet they remarkably did.

HT once again to Brené Brown in Dare to Lead.

Hope

We have a natural tendency to think that big events must have big causes. For instance, in one study, participants who were told that a plane had crashed and everyone died were more likely to believe it was a terrorist incident than one in which they were told a plane had crashed but people survived. It might also help explain why, when we want to roll that big lucky number to win, we might find ourselves giving the dice an extra shake before rolling, as if the extra effort might lead to the better outcome.

Normally, proportionality bias makes a lot of sense, but sometimes it leads us astray. Working with software, for example, might help train this out of us as a mere misplaced comma can bring entire systems grinding to a halt. And small changes to ecosystems, or, say, a small temperature rise on a planet, can lead to massive consequences.

Proportionality bias is considered one of the drivers of conspiracy theories. For example, we might be inclined to think that someone like Lady Diana couldn’t possibly have just died in a driving accident — there must be more to it. Or JFK couldn’t have been killed just by a lone gunman — there must be a larger plot at work.

Proportionality bias

The availability heuristic is a deceptively simple, almost too simple to notice, heuristic where we consider the likelihood of events by the ease with which relevant instances come to mind.

In simple terms, things that we can easily recall or where we can think of examples, we generally consider as more important or more common than other things. A heuristic is  a mental shortcut to solve a common problem.

If we were asked to consider the divorce rate in the community, we might evaluate that by considering how many of our acquaintances are divorced. If none of your friends are divorced, you’re naturally less likely to think the divorce rate locally will be high.

In many situations, it makes good sense to give credence to what you remember easily. However, in situations involving probabilities, in particular, the heuristic will lead us predictably astray such that more often I think of it as an availability bias — a predictable pattern of thought and behaviour leading to incorrect conclusions. 

So, the vividness of shark attacks causes us to overrate how likely they are to actually occur. Or we’re more likely to worry about lions than hippos, even though hippos kill more people each year than lions. Or the risk of being struck by lightning vs stuck by a car crossing a road. Or, the prevalence of violent crime on the news compared to the likelihood of you being a victim. Or the fact that it’s cold outside and yet the planet is gradually warming.

Here’s a 1973 Kahneman and Tversky paper: Availability: A Heuristic for Judging Frequency and Probability

Cognitive psychology sketches