Editing Positive feedback (section)

== Terminology ==
The terms ''positive'' and ''negative'' were first applied to feedback before [[World War II]]. The idea of positive feedback was already current in the 1920s with the introduction of the [[regenerative circuit]].<ref name=mindell>
{{Cite book
 |first       = David A.
 |last        = Mindell
 |title       = Between Human and Machine : Feedback, Control, and Computing before Cybernetics
 |date        = 2002
 |publisher   = Johns Hopkins University Press
 |location    = Baltimore, MD
 |url         = https://books.google.com/books?id=sExvSbe9MSsC
 |url-status     = live
 |archive-url  = https://web.archive.org/web/20180106192002/https://books.google.com/books?id=sExvSbe9MSsC
 |archive-date = 2018-01-06
|isbn        = 9780801868955
 }}</ref>

{{harvtxt|Friis|Jensen|1924}} described regeneration in a set of electronic amplifiers as a case where ''the "feed-back" action is positive'' in contrast to negative feed-back action, which they mention only in passing.<ref name="friis">{{Citation |last1=Friis |first1=H. T. |first2=A. G. |last2=Jensen |title=High Frequency Amplifiers |journal=Bell System Technical Journal |volume=3 |issue= 2|date=April 1924 |pages=181–205 |doi=10.1002/j.1538-7305.1924.tb01354.x}}</ref> [[Harold Stephen Black]]'s classic 1934 paper first details the use of negative feedback in electronic amplifiers. According to Black:
::"Positive feed-back increases the gain of the amplifier, negative feed-back reduces it."<ref name=black>
{{Citation |first=H. S. |last=Black |title=Stabilized feed-back amplifiers |journal=Electrical Engineering |volume=53 |pages=114–120 |date=January 1934 |doi=10.1109/ee.1934.6540374}}</ref>
According to {{harvtxt|Mindell|2002}} confusion in the terms arose shortly after this:
::"...Friis and Jensen had made the same distinction Black used between 'positive feed-back' and 'negative feed-back', based not on the sign of the feedback itself but rather on its effect on the amplifier's gain. In contrast, Nyquist and Bode, when they built on Black's work, referred to negative feedback as that with the sign reversed. Black had trouble convincing others of the utility of his invention in part because confusion existed over basic matters of definition."<ref name=mindell/>{{rp|page=121}}

These confusions, along with the everyday associations of positive with ''good'' and negative with ''bad'', have led many systems theorists to propose alternative terms. For example, Donella Meadows prefers the terms ''reinforcing'' and ''balancing'' feedbacks.<ref>{{cite book |last1=Meadows |first1=Donella H. |title=Thinking in systems : a primer |date=2009 |publisher=Earthscan |location=London |isbn=9786000014056}}</ref>