Just like machines, humans can run out of memory. We do it pretty often. Our available working memory can degrade as a result of decision fatigue over longer periods or context switching in the short term. When we crash, just like machines, our behaviour becomes erratic. We forget things and we look for shortcuts to free up our working memory and regain control. This unfortunate human behaviour has a profound impact on how we interact with the world and consequently, how we go about designing products.
We also live in a perpetual state of trying to pre-empt this inevitable failure. We are cognitive misers - we aim to make decisions while expending the least amount of mental energy possible. We look for shortcuts and rely on our primitive lizard brains to protect us by paying attention only to things that are likely to benefit our survival.
Learning to choose is difficult. Learning to choose well is more difficult. And learning to choose well in a world of unlimited possibilities is more difficult still, perhaps too difficult.
Bary Schwartz, The Paradox of choice
When we get presented with too much information or have too many decisions to make, we overload. When we do, we overlook the finer details of a product or service, lose focus or ignore an important learning moment. We still draw conclusions about the suitability of the product we are learning about.
Clearly, having a user overload when engaging with your design will have negative consequences for the overall quality of the experience.
Cognitive load theory suggests that learning happens best under conditions that are aligned with human cognitive architecture.
If products could design users, we would be a very different species indeed. But they don't. Designs must be made for humans, not the other way around. In doing so, we must factor in all the frailties of the human brain and body, front and foremost is the risk of dropping a user by way of cognitive load.
The architecture of how we present information to new users learning a product needs to be carefully considered and thoughtfully laid out, otherwise we risk failing to impress on our users the core information necessary to progress with the experience. We do this by managing cognitive load.
Cognitive load refers to the total amount of mental effort being used in the working memory. (source)
Three separate factors contribute to cognitive load and each consumes part of your working memory and trade off against each other:
Intrinsic load - This is the inherent level of complexity that your product has and depends on the number of features, expected domain expertise etc. While good UI design can greatly simplify the complexity of a product, it is unavoidable that the more complex a product is, the greater the level of intrinsic complexity it will possess.
Extraneous load - Extraneous cognitive load refers to any factors that are involved in the experience that require additional mental processing but do not directly contribute to the experience. Superfluous pictures, external interruptions, confusing animations or unexplained interactions all contribute to cognitive load, but do not contribute to improving how users interact with your product.
Germane load - These are the parts of your experience that contribute directly to cognitive load, while also contributing to the learnability or usability of the product.
The human mind has separate channels for processing both visual and verbal information. These can be work in tandem or work in conflict - depending on your design.
When using both visual and verbal information to communicate a learning experience for your product, try not to use both channels to reiterate each other - use them to complement each other instead.
Example: Listening to someone talk through every word of a slide show is boring. Watching them talk while they show a single word or phrases that is critically important to the theme being discussed on the slide is far more engaging and likely to result in learning.
The tolerance for cognitive load can vary from person to person. Some users start with a low tolerance for cognitive load, and typically prefer information presented in a visual, low detail format. These users include in peripheral factors like the source of the information other visual cues to quickly make a decision. These users typically click or search first, and read later.
Others, who have a higher cognition tolerance prefer to review information in greater detail before making a decision - facts, tables, figures and spreadsheets are all relevant to this user type.
Different persuasive techniques are required for each user group, and a good design must cater for both - providing easily accessible visual data for the first group and accessible layers of additional detail for those who prefer the second.
Tolerance for cognitive load can also change depending on environmental factors. For example:
Part 1 talks about the nature of human motivation and how it affects people's engagement with your experience (i.e. product + brand).
Part 2 details how the user sees themselves and how we can position your experience to make a product feel "just right". We also discussed how cognitive dissonance can cause users to abandon your product in favour of others.
My goal in writing part 3 was to focus on how you can successfully onboard and retain users, especially when dealing with potentially complicated or difficult to communicate products. I look forward to your feedback on whether I have achieved that successfully. Thanks!