Where does plateau collide?

A stretch in the course of learning a skill during which measured performance stops improving and holds level for a time, despite continued practice, before it may rise again: the learning curve flattens into a plateau even though effort is unbroken. Bryan and Harter's 1899 Studies on the telegraphic language, which followed telegraph operators as they learned to send and receive Morse, described such a plateau as the interval in which the lower-order habits are already automatic while the higher-order habits that carry the next gain are not yet formed. The referent is a period of stalled improvement on a performance-versus-practice curve, not a shape of land, an electrical phase in a cell, or a rung reached in a career.[1]

Unit

A flat interval on a performance-versus-practice curve, in trials or time

Recovery means

Improvement can resume once higher-order habits consolidate, and the curve rises off the plateau

Measured by

Detected as a flat segment in a learning curve of performance scored against amount of practice

The sustained phase of a cardiac action potential, during which the membrane voltage stays elevated and nearly level for a couple of hundred milliseconds before it falls: the plateau is held by an inward calcium current that roughly balances the outward potassium currents, and it sets the long duration of the heartbeat's electrical signal. Bers's 2002 Cardiac excitation–contraction coupling described how the calcium that enters the cell during this plateau triggers the internal release that drives contraction. The referent is a maintained level of membrane voltage in time, measured in millivolts and milliseconds, and it is unrelated to a raised landform, a stall in learning, or a levelling of a career.[2]

Unit

A maintained level of membrane voltage, in millivolts over milliseconds

Recovery means

The plateau ends when the outward potassium currents prevail and the membrane repolarises to rest

Measured by

Recorded by patch clamp or microelectrode as the level, duration, and shape of the action-potential plateau

The point in a working life at which the likelihood of a further promotion becomes low, so advancement up the organisation levels off even as the person keeps working: growth in rank and responsibility flattens, whether because the pyramid narrows near the top or because the fit for the next role is lacking. Ference, Stoner, and Warren's 1977 Managing the career plateau defined it as the position where the odds of additional hierarchical promotion are small, and distinguished the still-effective from the disengaged among those who reach it. The referent is a flattening of upward mobility in a career, judged by promotion history and prospects, not a shape of land, a stall in learning a skill, or a phase of a heartbeat.[3]

Unit

A flattening of upward mobility, judged by rank reached against prospects

Recovery means

Movement can resume through reorganisation, lateral moves, or new openings above

Measured by

Assessed from promotion history, time in grade, and the rated likelihood of further advancement