View source for Efficiency

[[Category:Basic concept]]
[[Category:Physics analysis]]
The '''efficiency''' of a [[selection step]] is defined as the fraction of desired [[events]] or [[objects]] that pass it. For instance, if 60% of genuine [[Electron|electrons]] in a sample pass the electron [[identification]], the identification efficiency is 60%. In practice, the efficiency that it is feasible to achieve must be balanced against the purity of the sample after the selection: one generally wants high efficiency and purity, but it is often not possible to increase one without decreasing the other. Which balance works best depends on the analysis demands and strategy.

The opposite of efficiency is '''inefficiency''', defined as 1 – efficiency.