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1. an expression of the change or effect produced by the variation in certain variables, or of the ratio between two different quantities.
2. in chemistry, a number or figure put before a chemical formula to indicate how many times the formula is to be multiplied.
Bunsen coefficient the number of milliliters of gas dissolved in a milliliter of liquid at atmospheric pressure (760 mm Hg) and a specified temperature. Symbol, α.
confidence coefficient the probability that a confidence interval will contain the true value of the population parameter. For example, if the confidence coefficient is 0.95, 95 per cent of the confidence intervals so calculated for a large number of random samples would contain the parameter.
correlation coefficient a numerical value that indicates the degree and direction of relationship between two variables; the coefficients range in value from +1.00 (perfect positive relationship) to 0.00 (no relationship) to −1.00 (perfect negative or inverse relationship).
diffusion coefficient see diffusion coefficient.
coefficient of digestibility the proportion of a food that is digested compared to what is absorbed, expressed as a percentage.
dilution coefficient a number that expresses the effectiveness of a disinfectant for a given organism. It is calculated by the equation tcn = k, where t is the time required for killing all organisms, c is the concentration of disinfectant, n is the dilution coefficient, and k is a constant. A low coefficient indicates the disinfectant is effective at a low concentration.
linear absorption coefficient the fraction of a beam of radiation absorbed per unit thickness of absorber.
mass absorption coefficient the linear absorption coefficient divided by the density of the absorber.
phenol coefficient see phenol coefficient.
sedimentation coefficient the velocity at which a particle sediments in a centrifuge divided by the applied centrifugal field, the result having units of time (velocity divided by acceleration), usually expressed in Svedberg units (S), which equal 10−13 second. Sedimentation coefficients are used to characterize the size of macromolecules; they increase with increasing mass and density and are higher for globular than for fibrous particles.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


1. The mutual or reciprocal relation of two or more items or parts.
2. The act of bringing into such a relation.
3. The degree to which variables change together.
Farlex Partner Medical Dictionary © Farlex 2012


The degree to which two or more variables are related in some fashion. A linear relationship between variables can be measured with Pearson's correlation or Spearman's rho.
Correlation may not mean causation.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.


Statistics The degree to which an event, factor, phenomenon, or variable is associated with, related to, or can be predicted from another; the degree to which a linear relationship exists between variables, measured by a correlation coefficient. See Cervical biopsy-cytology correlation, Clinical correlation, Correlation coefficient, Intertemporal correlation, Pearson correlation, Rank correlation.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


The degree to which changes in variables reflect, or fail to reflect one another. Correlations are said to be positive when the variables change in the same direction and negative when they move in opposite directions. A common fault in statistics is to assume that correlations are significant when they are not, that is, to assume unjustifiably that changes in variables are causally related.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005


a statistical association between two variables, calculated as the correlation coefficient r . The coefficient can range from r = 1.0 (a perfect positive correlation) to r = -1.0 (a perfect negative correlation), with an r value of 0 indicating no relationship between the two variables. Height and weight in humans are positively correlated (as values for height increase so do values for weight), whereas other variables give a negative correlation, e.g. as human age increases so mental agility tends to decrease.
Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005


1. The mutual or reciprocal relation of two or more items or parts.
2. The act of bringing into such a relation.
3. The degree to which variables change together.
Medical Dictionary for the Dental Professions © Farlex 2012

Patient discussion about correlation

Q. I have chronic hayfever problems in the mornings for the first hour.Seems to be a correlation with dairy produ I also got asthma 8 years ago at age 69, after having 2 pet cats. It is controlled with 2 puffs of Symbicord daily, am & pm. Anyone managed a complete cure?

A. Hey lixuri,you mean to tell me after after 25yrs as a therapist,All my patients had to do is drink water all day.i love it,how long does it take to work,an what does the patient do in the mean time if they have a asthmatic attack(drink WAter while you cant breath?-PLEASE SEND ME AN AANSWER.---mrfoot56.

Q. What correlation is there between Diet and Fitness? do i attain those two in a similar way? do i have to attain one in order to complete/gain the other ?

A. agree with dominicus. if you want to be healthier, you should keep your eye on what you eat and how often/how regular you do the exercise.
the result will be best if you can combine those two in balance portion and in healthy and wise manner.

Good luck, and stay healthy always..

More discussions about correlation
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References in periodicals archive ?
The estimates of genotypic correlation coefficient between eight characters showed close parallelism in direction with their corresponding phenotypic correlation coefficient.
In the form rP for the phenotypic correlation coefficient of x and y; rg for the genetic correlation coefficient; re for the environmental correlation coefficient; Hxy for the correlative heritability of trait x and y; H 2 for the heritability.The relative efficiency of indirect selection (CRy/Ry) (Zhao et al., 2005) is calculated by the following formula:
Now that the market has hit a bump in the road, day traders are looking much more closely at short-term correlations.
Table-2: Correlation between age, Fall Risk Score (FRS), Timed Up and Go (TUG) test scores.
The expected correlation coefficient of r= 0.6735 between predicted mesiodistal width of unerupted canine and premolars (PSCP) calculated through Melgaco's equation to the actual mesiodistal width of unerupted canine and premolars (ASCP) were also taken for sample size calculation.
Positive correlation was obtained between the two, however students score better in the MCQs (Delaram and Sharifi, 2014).
Is it possible to introduce a novel weighted correlation coefficient measure for IBNSs?
The correlation functions can depict some properties of uranium components, such as enrichment and mass.
DeMello et al., "Correlation between standardized uptake value and apparent diffusion coefficient of neoplastic lesions evaluated with whole-body simultaneous hybrid PET/MRI," American Journal of Roentgenology, vol.
There are certain advantages of canonical correlation analysis as compared to the dynamic time series techniques.

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