HFE UNIT 5 : Controls and Displays

Human Factors Ergonomics

Interaction Types

Categories of user activity with a system: instructing, conversing, manipulating, exploring, and responding.

Interface Types

The way users interact with a system; includes command-based, menu-based, GUI, natural language, etc.

Direct Manipulation

Interaction style where objects on screen behave like physical objects, allowing intuitive control (e.g., drag-and-drop).

Display

A visual, auditory, or tactile output used to communicate information about system state or environment to users.

Static Display

A non-changing or slowly changing visual element, like labels or printed warnings.

Dynamic Display

Displays that change frequently with system status (e.g., speedometers, altimeters).

Perceptual Principles (Display Design)

Principles ensuring displays are visible, legible, and easily understood (e.g., redundancy gain, absolute judgment limits).

Mental Model Principles

Design guidelines based on users' expectations and internal models (e.g., pictorial realism, moving part principle).

Attention-Based Principles

Display guidelines that guide attention effectively, such as proximity compatibility and minimizing information access cost.

Memory Principles

Principles that reduce cognitive load, like using consistency and providing predictive aids.

Control

A device used to regulate system operations, including switches, knobs, sliders, joysticks, and touchscreens.

Discrete Control

A control with a limited number of states (e.g., on/off switch, push buttons).

Continuous Control

A control allowing a range of values (e.g., volume dial, throttle lever).

Stimulus-Response Compatibility

The natural and expected relationship between controls and their corresponding outcomes.

Fitts’ Law

A predictive model stating that the time to move to a target depends on the distance and size of the target.

Hick-Hyman Law

A model indicating decision time increases logarithmically with the number of choices.

Control-Display Compatibility

The spatial and directional relationship between controls and the displays they affect; improves user performance.

Voice Control

A control input method using spoken commands; useful in hands-free or visually demanding contexts.

Control Layout Principles

Guidelines for effective control arrangement, including frequency of use, sequence of operation, and functional grouping.

Positioning Control Devices

Devices used for selecting positions on a display; includes mouse (indirect), touch screen (direct), joystick (velocity-based).