The User Experiance’s Memory
In our field, the concept of cognitive load closely relates to working memory. High cognitive load indicates a significant burden on working memory, making tasks appear challenging. To ensure a pleasant and usable experience, designers must prevent overload on the user's working memory.
Determining the working-memory capacity of our users can be challenging. While it is known that working memory has a limited capacity, the exact size varies among individuals. Factors such as education and IQ are positively correlated with working-memory capacity, while age has a negative impact. When targeting a specialized audience, such as experts, estimating their working-memory capacity becomes feasible. However, for a general audience, working-memory size tends to be more variable.
It's worth noting that members of your project team may have larger working-memory capacities compared to your target audience. Developers, in particular, often possess large working memories due to the complex nature of programming, which requires holding multiple elements in working memory simultaneously.
Consequently, your colleagues may find a task flow easy because it doesn't strain their working memory, but actual users may struggle due to working-memory limitations. It's important to remember that you are not the user.
A well-designed user experience should consider the needs of all users, including those with smaller working-memory spans. Therefore, a general design practice is to minimize the burden on users' working memory. In other words, ensure that users can easily access all the information necessary for a task without relying solely on their working memory.
External Memory
Although it may sound simple to limit the working-memory burden, certain tasks inherently possess higher complexity levels. How can we assist users in overcoming their working-memory limitations? In the example of performing addition, the task itself cannot be altered. However, we can facilitate the process by providing users with tools such as pen and paper, allowing them to write down numbers and intermediate results without relying solely on their working memory. This physical scratchpad acts as an external memory, alleviating the cognitive load.
External memory refers to any tool or user interface feature that enables users to explicitly save and access information required during a task. The same concept applies to web tasks. By supplementing working memory with a form of external memory, such as a virtual scratchpad, users can store all the necessary information without overloading their internal memory.
For instance, reading a difficult passage on a mobile device presents a task with high working-memory demands. Our studies reveal that users need more time to comprehend the same content on a small screen compared to a large screen, likely due to the increased cognitive load. The larger screen acts as a natural external memory, allowing users to refer back to previous paragraphs if needed. However, on a smaller screen, the limited visible area reduces the size of the external-memory scratchpad, forcing users to invest more time in recovering information.
Another common web task that burdens working memory is item comparison. Users must assess the pros and cons of multiple alternatives and make the best choice. Whether it's comparing hotels, shoes, or insurance plans, this task involves remembering available options and determining the optimal combination. Comparison tables and similar tools serve as forms of external memory, enabling users to select and compare items easily in a visually organized manner.
In some cases, users create their own external-memory tools. For example, using spreadsheets, files, or web notes to keep track of summer camps for their children, places to visit during a vacation, or articles to read.
During online shopping, many users save potential purchases in a shopping cart and make decisions at the end. Millennials engage in "page parking," opening interesting items in separate tabs for future review without interrupting their selection process.
These behaviors demonstrate how users create external memory to cope with tasks that demand significant working-memory capacity.
General Conclusion:
Different tasks impose varying working neurological and psychological systems
Reference
Baddeley, A.D., & Hitch, G. (1974). Working memory. In G.H. Bower (Ed.), The psychology of learning and motivation: Advances in research and theory (Vol. 8, pp. 47–89). New York: Academic Press.
