Cognitive Task Analysis

Cognitive Task Analysis (CTA) developed in response to an increase in the number of work tasks and systems that are dependent on cognitive processes. This method aims to identify sources of high cognitive strain as these are potential sources of error. Once these have been identified then devices can be developed that support the user by reducing the mental burden caused by a task. This method has been used successful in safety-critical industries such as rail and nuclear and it could have a similar impact on healthcare as this is a particularly stressful place to work and the consequences of error can result in serious harm to patients or even death. Put simply, when people are working under pressure and have a number of things on their minds then mistakes can happen.


Examples of ways that devices should support the user can include:


  • Providing a screen that displays all of the information entered into a device so that the user does not have to remember it.
  • User should be informed about what is going on with the system through appropriate feedback and display of information
  • Users should be able to easily identify, and recover from, errors.


A relevant example that is often cited when discussing medical device applications is that of infusion pumps. In order to administer a particular dose of a medication to a patient, a nurse will program an infusion pump to automatically deliver the drug. Programming the user-interface often involves navigating through and entering data into a number of different screens and a common problem with these types of devices is the lack of feedback given to the nurses as they progress. Nurses have to remember everything that they have previously entered which increases the load on the working memory and increases the cognitive strain. These are potential sources of error that would be identified during the CTA.

This type of analysis is used to investigate tasks that are primarily dependent on cognitive processes. It documents each of the thought processes and decisions that are required to complete a task.