Usability Issues

Automatic versus Controlled Processing

 

Answer the following two questions quickly

 

How do you pronounce the letters S H O P?

 

What do you do at a green light?

 

Continue

 

 

 

 

 

 

 

 

 

If you answered the last question "stop" you were using automatic processing instead of controlled processing. In controlled processing one would answer "go." We stop at red lights, not green. The second question did not logically follow the first, hence easily created the error.

How an individual understands and acts on information is either automatic or controlled and can vary depending on the situation. In automatic processing, the individual processes information, often unconsciously. Although necessary in many situations it can result in user errors in information systems.

Screens in information systems that seem to be adhering to the usual pattern, but actually are not what would logically be expected will often create errors as the user processes what he or she expected, rather than what is actually presented. This can be a result of multi-tasking or time pressures.

Controlled processing, which is much slower, results when individuals pay conscious attention to what a screen actually says.

Two ways to avoid errors from automatic processing are:

• When you must do something out of the ordinary, create what are known as "cognitive bumps," or something out of the ordinary that will flag the users attention.
• Avoid varying from an expected or logical pattern.

 

If a high rate of user errors are seen in certain processes, the user could be using automatic processing instead of cognitive processing. When there is a high rate of errors in a given spot, don't immediately look to for more training as the solution. Many problems are solved by tweaking the system, not investing hours in training.

A story from my experience illustrates this point. We were having trouble with the night nurses who would remove IVs that needed to be refrigerated from the refrigerator in the central nursing station and carry them to the wing to which they were assigned and leave them sitting at their desk their. Training was given several times with minimal change in this procedure. When someone finally was bright enough to ask a few nurses why they did this they were told that they did not have time to go back to the central station for the IV. Solution: a small refrigerator on each wing. Immediate change in behavior. Morale: Look at systems before blaming the user.

See also the Usability section on this chapter's home page.

Created January 20, 2012