Parasuraman, Sheridan, and Wickens
A model for types and levels of human interaction with automation
Parasuraman, Sheridan, and Wickens. 2000. (View Paper → )
…Developments in hardware and software now make it possible to introduce automation into virtually all aspects of human-machine systems. Given these technical capabilities, which system functions should be automated and to what extent? We outline a model for types and levels of automation that provides a framework and an objective basis for making such choices. Appropriate selection is important because automation does not merely supplant but changes human activity and can impose new coordination demands on the human operator.
10 Levels of Automation
- The human does everything manually—no computer assistance.
- The computer offers a full set of decision alternatives, but the human makes the final choice.
- The computer narrows down the options to a few possibilities for the human to choose from.
- The computer recommends a single decision alternative while the human retains the authority to accept or select a different option.
- The computer executes the recommended alternative if the human does not intervene.
- The computer initiates execution but allows only a limited time window during which the human can veto the action.
- The computer makes the decision and automatically acts if the human does not respond within the short time frame.
- The computer fully executes the decision and then informs the human after the fact.
- The computer conducts both decision making and action implementation with minimal or no human involvement.
- Full automation—the system operates entirely autonomously, with the human out of the loop.
4-Stage Model of Human Information Processing
This model describes the sequential stages through which a human operator processes information in an automated system:
- Information Acquisition: Sensing and registering incoming data.
- Information Analysis: Processing, integrating, and making sense of the data.
- Decision and Action Selection: Evaluating alternatives and selecting the appropriate response.
- Action Implementation: Executing the chosen decision.
This paper provided a clear, systematic framework for understanding human interaction with automation. It emphasised that automation isn’t simply an all-or-nothing switch but exists along a continuum—both in terms of the tasks that can be automated (acquisition, analysis, decision, and action) and the levels of automation applied. This perspective helped shift the focus toward designing systems that balance the benefits of automated decision making with the risks of reduced human involvement, such as loss of situational awareness, complacency, and skill degradation.