This module first presents a general model of the basic components of human-system interactions.  The model will be used throughout the course to provide a conceptual framework for Human Factors considerations in system and workplace design.

Second, the relative strengths and weaknesses of both the human and machines/systems are described.  Understanding these concepts is important in determining, early in system design, what functions are to be performed by the human and what functions are to be performed by the system.  We wish to:

• Utilize the strengths of both the human and system,
• Avoid function assignment to the weaknesses/limitations of either.

Next, human variability is addressed.  Machine/systems are built to function within specific tolerances, so that identical machines have identical, or nearly identical, characteristics.  By contrast, humans vary due to genetic and environmentally determined differences.  These differences must be taken into account when designing products, tools, machines, and systems to "fit" the target user population.  Human capabilities and attributes differ across:

• Sense modalities,
• Cognitive functioning,
• Reaction time,
• Physical size and shape,
• Physical strength.

The module takes about 30 minutes to complete.