The Importance Of Human Errors In HCI Design

In any complex system, human operators are the biggest sources of error. The main reasons for human errors are due to incomplete specification, design defect and error in implementation. These errors lead to a poorly designed human-computer interface. Failure modes are common and certain conditions will make it more likely for a human operator to make a mistake. Therefore a good HCI design can help the operator to perform correctly and also protect the system from common type of errors. However, for safety critical system there is no well defined procedure for construction of such a system.

In an embedded system, human operators are the weak link and the cost, size, power and complexity are especially limited. So the design of interface must

But the system cannot react well for unusual situation. Human operators are needed to handle the system. Human usually handle novel occurrences in a better manner when compared to machines. But they cannot perform repetitive task well. Thus most of the time the operator just monitors the system when there is no problem, and handle failures in emergency situation. It is a major issue in HCI design, because the operator not involved in the control of the system, they tend to become bored and the user responsiveness is dulled. This situation is called as operator drop-out. The operator make more mistakes and not able to recover quickly in real emergency situation.

When the operator routinely involved in the control of the system, operator may adapt to a common mode of operation. Thus the HCI must be designed to keep the user alert and to make the user interested in his or her job allowing the user to operate the system in a more comfortable manner.

The major contributing factor to human error is stress. Unfamiliar or exceptional occurrences that may cause a high loss of money, data, or life or time critical task are reasons for stressful situation. When there is a raise in stress level, it may tend to degrade the performance of human. To handle extreme situations, the user interface must provide appropriate feedback to the user. (ii) Types of

Solutions are based on the stored rule of the type “if state x then action y “. Through training or through experience these procedures can be learned. The performance is characterized by feed-forward control. An example of rule-based behavior is opening a document in a familiar word processor.

Knowledge- based behavior

Knowledge-based behavior handles unfamiliar problems. It is applicable when the environment is new and no stored rules are available from previous encounters. An example of knowledge-based behavior is learning to use a new spreadsheet application or new gaming program.

Mistakes

Mistakes are assigned to rule-based behavior and knowledge-based behavior. Errors at the level of intention are called as mistakes. It can be defined as follows:

• The action takes place as planned but the plan itself is wrong

• Planning failures

• The plan is not adequate to achieve intended outcome, the error is one of inappropriate intention

• Failures in the selection or application of problem-solving rules

• Errors are due to application of wrong