Effective time constant as a quantifiable construct predictive of task difficulty¶

Theory · All theories
Evidence · 3 claims (3 for) · 1 study (1 causal), q2 · 0 of 1 report an effect size · 3 claims rest on one study

Description¶

The effective time constant (te) is a construct embodying machine properties described by the equations of motion of the vehicle and the operator property of level of threshold of perception of vehicle output. It is proposed as a basic measurable parameter of the man-machine combination, an independent variable predictive of task difficulty. Experimentation showed te to be related to final level of precision of control and to rate of learning, and level of performance is related to the interactive effect of te and steady-state system gain expressed as the product (kte).

Design Implications¶

Context¶

Requirements¶

• The threshold is an effective threshold defined by operator reaction to system output, arbitrarily assumed fixed at a reasonable, empirically determined value

Constraints¶

• Machine properties of gain, frequency and damping are not, as individual parameters, strongly related to control behavior; their proper combination into te was shown to be related to performance

Target Learners¶

• trainee vehicle operators

Target Learning Objectives¶

• manual control skill acquisition

Claims¶

• Gain-effective time constant product is slightly superior to forcing function amplitude as an adaptive variable [+W]
• Manual adaptation is slightly superior to automatic adaptation in adaptive training of manual control [+W]
• System compensation as implemented is not a satisfactory adaptive variable [+W]

Related Theories¶

• Machine-controlled adaptive training: task difficulty varies as a function of trainee performance

Examples¶

• Sequence adaptive difficulty by increasing gain first, then lengthening the effective time constant

Key Sources¶

• Norman, D. A.; And Others. (1972). Adaptive Training of Manual Control: 1. Comparison of Three Adaptive Variables and Two Logic Schemes. Life Sciences, Inc. https://eric.ed.gov/?id=ED059585 doi:10.1037/e426822004-001