To understand cognitive load theory, you first have to understand the brain activity (working memory) used at the very moment a task is being completed. That's because working memory sorts all external stimuli and short-term memory, and, when needed, pulls memories from long-term memory. For example, you can think of working memory as the computer's RAM, and long-term memory as the hard drive.
A common misconception — or a very important insight, depending on how you look at it — is this: working memory and short-term memory are often used interchangeably in many places, but strictly speaking they have different meanings. Working memory processes (sorts, recalls) information, whereas short-term memory plays the role of filtering out information that's not important for long-term memory.
One of the cases we most frequently run into while using the internet is the hyperlink.
Before any information search happens, working memory already 1) understands that when you mouse over a particular image or title, a blue or black underline appears, and 2) understands the concept that clicking such a title takes you to a related page. |
While searching on a portal site or reading a particular article, we easily run into (previously unfamiliar) concepts like blue-underlined text or black-underlined text. For even basic information search to work, working memory has to already know in advance what the concept of "blue text" means. In that sense, long-term memory knows (classifies) that blue text is a link, and working memory clicks the link to get more detailed information (recall/use). Short-term memory, meanwhile, remembers the location of impressive information or an article and plays the role of either taking you back to it once, or, as enough time passes (and you stop revisiting it), gradually making you forget the location or contents of that article.
So in practice, what are you supposed to do about it?!
Among those who popularized the application of cognition-based theory in web design, Steve Krug is known as one of the most influential. Through his book Don't Make Me Think, he gives many designers a core set of guidelines. Listing six of the most representative ones below, mixed with my own personal TMI:
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(사용자를) 생각하게 하지 마!
<Dont Make Me Think>는 사용성에 대한 관심이 한창 무르익었던 2000년대 초중반에 쉽고 간결하게 사용성이 무엇인지를 구체적인 사례 중심으로 소개하여 큰 인기를 얻었던 책이었다. 3차 개정판은 초
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1. Make things as self-evident (obvious) as possible, so no explanation is needed. That's because people spend far less time on our product (app or web) than we expect. In practice, people often stop at benchmarking (copying) elements from famous (familiar) products. In that process (with those elements being treated as "no big deal" design bits), it can happen that the purpose of the service drifts from its original intent, or that the positioning relative to the target user becomes ambiguous. That's why a serious approach and understanding of the mental model is necessary.
2. Users always make the best choice in that moment, not the absolute best. Meeting the minimum conditions is what matters. In other words, if something is easy and intuitive, especially if it's used habitually, the user will no longer waste time hunting for a better option. Once that happens, they end up so-called "self lock-in," and from then on a virtuous cycle kicks in of justifying their own choice.
3. Usability is appropriate when a person with average ability or experience can use the system to achieve their goal.
4. The biggest motivation users have for using our product (app or web) is, for the most part, the desire to save time (simplicity and convenience).
5. The Back button is the most frequently used interface on the web. It's an insight that often gets overlooked. And this function is handled by working memory.
6. The Home button gives the user a sense of security that even if they get lost inside the site, they can always start over.
In addition to Krug, usability experts such as the Nielsen Norman Group also wrestle with cognitive overload in design and propose various solutions. They describe skilled UX design as being like aerodynamic design. When a user is using our product (app or web) and hits a collision like excessive cognitive load, it's as if the whole airplane crashes: the user loses their way, and the service loses the user. That's why they argue that designers need to more actively make sure users don't have to think.
There's some disagreement over whether a "smooth UX where users don't have to think" is always right, since not every company's design ethics are necessarily appropriate — but that's somewhat off-topic for this post. And since I fully empathize with the author's intent in the context of the words he used, I'll skip any more TMI here.
Finally, I'll close this post by introducing their guidelines for preventing cognitive overload (or perhaps information overload).
1. Cognitive load is any information that adds to working memory. Cognitive overload occurs when too much information interferes with decision-making and the user experience.
2. To avoid visual clutter, you should use various content types and a structured page layout.
3. Using hidden menus lets you manage the number of menu items visible at once, but decreases the probability that users will find the menu.
4. Strategies like chunking (grouping data to make it easier to remember) and multi-step forms with progress indicators protect users from cognitive overload.
5. Clearly recognizable UI elements leverage the user's existing knowledge, so the user doesn't have to think much. New and original features can be explained through onboarding.
6. You need to think carefully about how users actually think, then structure your IA accordingly. Usability tests like card sorting and tree testing can reveal the most intuitive navigation for your target group.
7. In addition to typos and grammatical mistakes, inconsistencies in visuals and functionality also disrupt the user's overall task.
8. Where possible, it's good to eliminate duplication. You have to carefully design ways to minimize the number of steps the user has to go through or the amount of effort required.
