Congratulations! None of your users notice how beautifully designed your app is. None of them think about your app, at least while they are using it. Why is this good news for a product manager? This means that your user’s cognitive load is not excessive and they are just enjoying the lightness of completing desired tasks instead of trying to figure out where to click on or which content to focus on.
Our brains are just like computers, or vice versa. They have limited processing capacity. Cognitive load refers to this limited capacity and to the total amount of information your working memory can handle. We’ll explain in detail, let’s dive into the world of cognitive psychology and blend it with user experience.
Multistore Model of Memory
Have you heard of the Multistore Model of Memory? You probably know what it is but don’t know the model’s name. It is a human information processing model proposed by Richard Atkinson and Richard Shiffrin in 1968. According to this model, information processing has three main parts: sensory memory, short-term memory, and long-term memory. Sounds familiar, right?
So, the environmental input and information comes to sensory memory and then passes into short-term memory where it is actively held for a short period of time. Imagine your friend asks you to hold a phone number in mind for a moment. When he says the numbers, although you are still exposed to different inputs such as car horns your sensory memory filters them and the numbers could pass into your short-term memory. After a short period of time, your friend asks for the numbers and you can tell them. Although it is known that our short-term memory is limited with seconds, there are different theories on the capacity of our short-term memory. The most cited one known as Miller’s Law limits our short-term memory to 7±2 elements (The Magical Number Seven, Plus or Minus Two: Some Limits on our Capacity for Processing Information, George Miller, 1956). Later on, Nelson Cowan proposed that 4±1 units would be more realistic.
During this process, the information passes into the long-term memory which has no known capacity limit. Long-term memory doesn’t only consist of a group of learned information but also of structures that permit us to perceive, think, and solve problems. These structures are called schemas where information is stored.
Although in some situations and according to some theorists, short-term memory and working memory are used interchangeably, they are different in our case. They both have limited capacity and stores for a short period of time. The Human Memory depicts short-term memory as a “scratchpad” for the temporary recall of the information, the brain’s post-it note. However, working memory refers to the whole framework of processing and structure for temporary storage and manipulation of information. Hence, short-term memory is a part of the working memory. We can relate working memory to consciousness.
The capacity of the working memory is a bit different from short-term memory. Working memory has a capacity of 2-4 elements, because it is also processing the information in new ways and combining it with other elements than just simply remembering the information.
Cognitive load refers to the total amount of information your working memory can handle or to the amount of working memory resources.
John Sweller, an Australian educational psychologist, published his work “Cognitive Load Theory, Learning Difficulty, and Instructional Design” in 1988 (reworked and republished in 1994). Cognitive Load Theory stressed that new information is processed and stored by the capacity and duration-limited working memory and then stored in an unlimited capacity long-term memory. In its core, the theory aimed to explain how the information processing load in tasks related to learning affects students’ ability to process this information and pass it into long-term memory. His work has broad implications for instructional design.
Primary Knowledge, Secondary Knowledge
In a podcast with Connie Malamed, John Sweller explains that one of the categories of knowledge is primary or secondary knowledge. The primary knowledge is where you have evolved to acquire it. He gives an example of our ability to learn native languages. Although languages are very complicated, we acquire it easily. Secondary knowledge is the knowledge we are able to acquire consciously, with a lot of effort. An example of this would be learning other languages other than your native language/s.. For the latter, we need to take into consideration our cognitive load and hence, our working memory.
Once information goes into long-term memory, we can bring it back to working memory. The working memory is limited when it is processing new information, however, it is unlimited when it comes to dealing with the information we obtain from long-term memory.
“The more you know, the easier it is to know even more again” John Sweller
Smashing Magazine’s example explains how this process occurs. While you are reading this blog post, you came across to blue colored, underlined texts. To fully understand this blog post, your working memory needs to know what blue colored, underlined texts are. Your long-term memory says that these particular texts are links. So, your working memory handles the clicking and checking the link process. And when you come back to this blog post, your short-term memory helps you to remember which paragraph you were up to, but only for a short period of time.
Categories of Cognitive Load
According to the Cognitive Load Theory, there are three different types of cognitive load: intrinsic, extraneous and germane.
Intrinsic cognitive load simply refers to the complexity of the information. For example, the calculation of 5×5 is a lot less than solving a long derivative problem. The first is retrieved from the long-term memory, yet the latter should be processed in the working memory.
Extraneous cognitive load is determined by how the information is presented and what the learner is required to do by the instructional procedure.
For example, describing a square verbally is a lot harder than describing it visually, and it is harder for learners to understand it verbally. Likewise, describing abstract terms such as “truth” is a lot harder to describe visually than verbally.
Germane cognitive load refers to the working memory resources that are devoted to dealing with intrinsic cognitive load rather than extraneous cognitive load. Germane cognitive load is produced by the construction of schemas and reducing the difficulties caused by distractions, extraneous cognitive load.
Avoid Cognitive Overload
Trying to process many elements at a time slows down our learning process and results in frustration and annoyance. Although reducing cognitive load is one of the main topics of education, cognitive load finds itself a place to improve user experience in the digital world too.
Let’s dive into what you can do to avoid the cognitive overload of users.
Breaking a Myth
Remember George Miller’s magic number 7? Many confused designers misunderstood and misused this finding by limiting themselves to, for example, adding no more than 7 options on a navigation bar. On a navigation bar, the information is visually present and users don’t have to use their short-term memory to navigate your app.
It is up to your choice whether to add more options or not, however, keep in mind that on a menu tab, recognition is more important than recall. Your menu tab shows your users which options are available and the users recognize the one they need. They don’t need to recall the options.
In the field of cognitive psychology, ”chunk” is an organizational unit of memory. The most common example of chunking is remembering phone numbers. A chunked phone number +1-234-567-8900 is easier to remember and scan than a long, unchunked phone number +12345678900.
In the area of UX, chunking is breaking up content into small, distinct units of information.
Chunking your app’s content makes scanning easier for the user and improves their understanding and recall of your content.
Know the Mental Models
A mental model is what the user believes about the system at hand. Knowing which mental models users have built before entering your app will give you an idea of what the users expect from your app. If your users are familiar with how your app functions, then their working memory will process less and they will retrieve information from their long-term memory.
If you want to learn more about mental models, check out “What Do Mental Models Mean for User Experience?”
Avoid Vague Interface
A confusing user interface is one of the biggest actors of cognitive overload. Users shouldn’t try to figure out which button they should use to go back, to open a particular page or which page a button directs to.
Apart from using clear labels, you can also use conventional user interface features. Use familiarity with your app’s and user’s benefit.
If you are introducing a brand new feature, make sure that you are providing the clear instructions during the onboarding process.
If you keep consistency in your app, users learn how to navigate your app a lot easier, which reduces their cognitive load. If a user is taking a moment to understand one of the features resulting from inconsistency, then they are using their working memory.
Avoid Unnecessary Actions and Choice Paralysis
Users’ working memory focuses on achieving one task, unnecessary action on the path increases the cognitive load and might distract the users. Avoid extraneous cognitive load.
The opportunity to choose among many others is sometimes less of an opportunity and more of a burden. For your app, having too many options on the same page could overwhelm the users and increase the cognitive load.
The attention of your user is highly valuable. These tips aim to reduce the cognitive load of your users and navigate your app without frustration and distractions. But at the end of the day, it all depends on your app. You may want the intrinsic cognitive load to be a bit high because you want users to learn something on your app, or the opposite. Either way, cognitive load, and cognitive psychology offer valuable insights to product managers.