Editing Trial and error (section)

==Examples==
Trial and error has traditionally been the main method of finding new drugs, such as [[antibiotics]]. [[Chemist]]s simply try chemicals at random until they find one with the desired effect. In a more sophisticated version, chemists select a narrow range of   chemicals it is thought may have some effect using a technique called [[structure–activity relationship]]. (The latter case can be alternatively considered as a changing of the problem rather than of the solution strategy: instead of "What chemical will work well as an antibiotic?" the problem in the sophisticated approach is "Which, if any, of the chemicals in this narrow range will work well as an antibiotic?") The method is used widely in many disciplines, such as [[polymer technology]] to find new polymer types or families.

Trial and error is also commonly seen in player responses to [[video game]]s - when faced with an obstacle or [[Boss (video gaming)|boss]], players often form a number of strategies to surpass the obstacle or defeat the boss, with each strategy being carried out before the player either succeeds or quits the game.

[[Sports team]]s also make use of trial and error to qualify for and/or progress through the [[playoffs]] and win the [[championship]], attempting different strategies, plays, lineups and formations in hopes of defeating each and every opponent along the way to victory.  This is especially crucial in [[Playoff format#Best-of formats|playoff series in which multiple wins are required to advance]], where a team that loses a game will have the opportunity to try new tactics to find a way to win, if they are not eliminated yet.

The [[scientific method]] can be regarded as containing an element of trial and error in its formulation and testing of hypotheses. Also compare [[genetic algorithm]]s, [[simulated annealing]] and [[reinforcement learning]] – all varieties for search which apply the basic idea of trial and error.

[[Evolution|Biological evolution]] can be considered as a form of trial and error.<ref>{{cite journal|last=Wright|first=Serwall|title=The roles of mutation, inbreeding, crossbreeding and selection in evolution|journal=Proceedings of the Sixth International Congress on Genetics|date=1932|number=6|series=Volume 1|page=365|url=http://www.esp.org/books/6th-congress/facsimile/contents/6th-cong-p356-wright.pdf|access-date=17 March 2014}}</ref> Random mutations and sexual genetic variations can be viewed as trials and poor reproductive fitness, or lack of improved fitness, as the error. Thus after a long time 'knowledge' of well-adapted genomes accumulates simply by virtue of them being ''able'' to reproduce.

[[Bogosort]], a conceptual sorting algorithm (that is extremely inefficient and impractical), can be viewed as a trial and error approach to sorting a list. However, typical simple examples of bogosort do not track which orders of the list have been tried and may try the same order any number of times, which violates one of the basic principles of trial and error. Trial and error is actually more efficient and practical than bogosort; unlike bogosort, it is guaranteed to halt in finite time on a finite list, and might even be a reasonable way to sort extremely short lists under some conditions.

[[Jumping spider]]s of the [[genus]] ''[[Portia (spider)|Portia]]'' use trial and error to find new tactics against unfamiliar prey or in unusual situations, and remember the new tactics.<ref name="HarlandJackson2000Cats">{{Cite journal
 |author1       = Harland, D.P.
 |author2       = Jackson, R.R.
 |name-list-style = amp
 |year          = 2000
 |title         = "Eight-legged cats" and how they see - a review of recent research on jumping spiders (Araneae: Salticidae)
 |journal       = Cimbebasia
 |volume        = 16
 |pages         = 231–240
 |url           = http://www.cogs.susx.ac.uk/ccnr/Papers/Downloads/Harland_Cimb2000.pdf
 |access-date    = 5 May 2011
 |url-status       = dead
 |archive-url    = https://web.archive.org/web/20060928164131/http://www.cogs.susx.ac.uk/ccnr/Papers/Downloads/Harland_Cimb2000.pdf
 |archive-date   = 28 September 2006
}}</ref> Tests show that ''[[Portia fimbriata]]'' and ''[[Portia labiata]]'' can use trial and error in an artificial environment, where the spider's objective is to cross a miniature [[lagoon]] that is too wide for a simple jump, and must either jump then swim or only swim.<ref name=JacksonEtc2006ConfineProb>{{cite journal | last=Jackson | first=Robert R.
  |author2=Fiona R. Cross |author3=Chris M. Carter
  | title=Geographic Variation in a Spider's Ability to Solve a Confinement Problem by Trial and Error
  | journal=International Journal of Comparative Psychology | year=2006 | volume=19 | issue=3
 | pages=282–296
  | doi=10.46867/IJCP.2006.19.03.06
 | url=http://escholarship.org/uc/item/53c3x1w9;jsessionid=34833B994B69E2CA4DA97613EA34F531#page-1
  | access-date=8 June 2011| doi-access=free}}</ref><ref name=JacksonEtc2001ConfinProb>{{cite journal | last=Jackson | first=Robert R.
  |author2=Chris M. Carter |author3=Michael S. Tarsitano
  | title=Trial-and-error solving of a confinement problem by a jumping spider, ''Portia fimbriata''
  | journal=Behaviour | year=2001 | volume=138 | issue=10 | pages=1215–1234
  | jstor=4535886| publisher=Koninklijke Brill | location=Leiden|issn=0005-7959 | doi=10.1163/15685390152822184}}</ref>