Where does fading collide?

In behaviour analysis and instruction, fading is the gradual withdrawal of a prompt or supporting cue so that a learner comes to respond correctly to the natural stimulus on its own. Terrace's 1963 work on discrimination learning without errors showed that an easy discrimination could be transferred to a hard one by slowly fading in the harder cue, letting the learner acquire it with almost no mistakes. The referent is the planned removal of instructional support over trials, measured by sustained correct responding as the prompt is thinned, and it is a different construct from the fluctuation of a radio signal.[1]

Unit

The level of prompt support that can be removed while correct responding holds

Recovery means

Not applicable

Measured by

Tracked by accuracy and error rate as the prompt is thinned step by step toward independent responding

In radio communications, fading is the variation in the strength of a received signal over time, caused chiefly by multipath propagation, where copies of the signal arriving by different paths add and cancel as the receiver or scatterers move. Clarke's 1968 statistical theory of mobile-radio reception modelled the received field as a sum of scattered waves, yielding the fading statistics that describe how deeply and how often the signal drops. The referent is a stochastic fluctuation of channel gain, measured by its depth, rate, and distribution, and it is unrelated to the deliberate withdrawal of an instructional prompt.[2]

Unit

The depth and rate of fluctuation in received signal strength

Recovery means

Diversity and equalisation techniques recover the signal by combining paths or copies so that deep fades on any one are compensated

Measured by

Characterised by fade depth and duration and by the statistical distribution of the received envelope