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Encyclopedia > Scientific control

A scientific control augments integrity in experiments by isolating variables as dictated by the scientific method in order to make a conclusion about such variables. In a controlled experiment, two virtually identical experiments are conducted. In one of them, the treatment, the factor being tested is applied. In the other, the control, the factor being tested is not applied. For example, in testing a drug, it is important to carefully verify that the supposed effects of the drug are produced only by the drug itself. Doctors achieve this with a double-blind study in a clinical trial: two (statistically) identical groups of patients are compared, one of which receives the drug and one of which receives a placebo. Neither the patients nor the doctor know which group receives the real drug, which serves both to curb researchers' bias and to isolate the effects of the drug. In the scientific method, an experiment (Latin: ex- periri, of (or from) trying) is a set of observations performed in the context of solving a particular problem or question, to support or falsify a hypothesis or research concerning phenomena. ... In computer science and mathematics, a variable (pronounced ) (sometimes called an object or identifier in computer science) is a symbolic representation used to denote a quantity or expression. ... Scientific method is a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. ... This article does not cite any references or sources. ... The double blind is ray charles is ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesis ray charlesof the scientific method, used to prevent research... In health care, including medicine, a clinical trial (synonyms: clinical studies, research protocols, medical research) is a process in which a medicine or other medical treatment is tested for its safety and effectiveness, often in comparison to existing treatments. ... A patient having his blood pressure taken by a doctor. ... For other uses, see Placebo (disambiguation). ... For other senses of this word, see bias (disambiguation). ...


Necessity of controls

Controls are needed to eliminate alternate explanations of experimental results. For example, suppose a researcher feeds an experimental artificial sweetener to sixty laboratory rats and observes that ten of them subsequently die of dehydration and vomit. The underlying cause of death could be the sweetener itself or something unrelated. Perhaps the rats were simply not supplied with enough water; or the water was contaminated and undrinkable; or the rats were under some psychological or physiological stress that caused them not to drink enough; or a disease dehydrated them; or their cage was kept too hot. Eliminating each of these possible explanations individually would be time-consuming and difficult. Instead, the researcher can use an experimental control, separating the rats into two groups: one group that receives the sweetener and one that doesn't. The two groups are kept in otherwise identical conditions, and both groups are observed in the same ways. Now, any difference in morbidity between the two groups can be ascribed to the sweetener itself--and no other factor--with much greater confidence. In other cases, an experimental control is used to prevent the effects of one variable from being drowned out by the known, greater effects of other variables. For example, suppose a program that gives out free books to children in subway stations wants to measure the effect of the program on standardized test scores. However, the researchers understand that many other factors probably have a much greater effect on standardized test scores than the free books: household income, for example, and the extent of parents' education. In scientific parlance, these are called confounding variables. In this case, the researchers can either use a control group or use statistical techniques to control for the other variables.A control is something you keep the same so if your doing a science project do not change the control!!! A sweetener is a food additive which adds the basic taste of sweetness to a food. ... This is an article about wild rats; for pet rats, see Fancy rat Species 50 species; see text *Several subfamilies of Muroids include animals called rats. ... In statistics, a spurious relationship (or, sometimes, spurious correlation) is a mathematical relationship in which two occurrences have no logical connection, yet it may be implied that they do, due to a certain third, unseen factor (referred to as a confounding factor or lurking variable). The spurious relationship gives an...


See also


  Results from FactBites:
 
Scientific control - Wikipedia, the free encyclopedia (280 words)
A scientific control augments integrity in experiments by isolating variables as dictated by the scientific method in order to make a conclusion about such variables.
The scientific control is used as a constant to show the effect a given environment has on certain variables.
A control sample where a negative result is expected, to help correlate a positive result with the variable being tested.
Control - Wikipedia, the free encyclopedia (271 words)
A scientific control to isolate variables in experiments
Control (musician), a noise project of Thomas Garrison
Control (le Carré character), the fictional Head of British Intelligence in several of John le Carré's spy novels
  More results at FactBites »

 
 

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