Short-Term Memory Limitations and Technology Design

Short-term memory and working memory largely influence the way we design interfaces. Why are control panels, from car instrument panels to cockpit controls, designed the way they are designed? Why is the layout of the iPhone so appealing to its users? Why can we sometimes navigate iPhones and apps without even looking at the screen?

Most interfaces are designed to appeal to human’s short term memory and working memory. Take cockpit controls. Most aircrafts use a T-shape arrangement: altitude indicator is at the top, heading indicator is underneath the altitude indicator, speed is to the left, and altimeter is on the right.

This T-shape is a good example of how an interface can be designed for short-term memory and working memory. Short-term memory can only handle small amounts of information; therefore, a large, complicated control panel without any organization wouldn’t be easy to store in short-term memory. But, when these confusing dials and gauges are arranged into a familiar shape, short-term memory can store their location and meaning more easily. It is also more conducive to working memory; the specific arrangement of the gauges can help the pilot to process what each gauge means and determine whether or not they are cruising at a proper altitude, in the correct direction, etc.

How are the interfaces of things such as iPhones and apps designed to benefit our short-term and working memory? The simple and navigable interface of the iPhone is very conducive to short-term memory and working. Color plays a big part remembering the meaning of all those little square icons on your screen.

Which display is more memorable?

There are 24 icons on the iPhone screen; without the brightly colored display, it might be much more difficult to tell all of them apart. If one looks closely, the icons for FaceTime, Phone, and Messages, are all green; they are also the 3 ways you can communicate with your contacts. Because these 3 icons are the same color, it is easier to remember that they have similar purposes. The icons for the iTunes Store and Music would be very similar, if it were not for the difference in color that helps differentiate them. If it were not for the color of the apps, we would most likely become confused; however, the bright colors help assist short-term memory by creating a connection between color and purpose.

To summarize, designers can do things such as arrange a confusing interface into a more recognizable shape or take advantage of color to create a more memorable design. Next time you're looking the dials of a TV, the screen of your iPhone, or the layout of your tablet or E-Reader, think about what makes you remember what buttons do what, or what makes the interface you're looking at so easy to remember!

Below are some interesting papers on how arrangement and color can affect short-term memory. 

Color and Short-Term Memory Retention

http://homepages.stmartin.edu/fac_staff/molney/website/SMU%20Bio%20Journal/Richman%202006.pdf

Shapes and Short-Term Memory

http://www.ncbi.nlm.nih.gov/pubmed/18717388