Before entering fully into the meaning of the term normal curve, it is necessary to proceed to discover the etymological origin of the two words that give it its shape:
-Curve is a word that derives from Latin, exactly from “curvus” which can be translated as “curved”.
-Normal, on the other hand, also comes from Latin. In his case, it is the result of the sum of two perfectly delimited components: the noun “norm”, which is synonymous with “rule” or “model”, and the suffix “-al”, which is used to indicate “membership” or “relationship”.
A curve It is that which departs continuously from the straight direction, although without creating angles. The line used to graphically represent the magnitude of a phenomenon according to the values of one of its variables is also called a curve. NormalFor its part, it is what is natural or what works as the norm.
These ideas can help us understand what a normal curve, although the concept has a specific use in the field of statistics. The normal curve is called the gaussian distribution: the probability distribution of a continuous variable that is usually close to a real phenomenon.
The use of a normal model allows us to assume that the observations derive from the sum of independent causes. The normal curve, in this framework, serves to model social and natural phenomena in a way that approximates the reality.
The graphical representation of the normal curve is known as gaussian bell. This flared line is symmetric with respect to a certain parameter: there is a concave middle zone, which has in the center the mean value of the function, and two convex ends that tend to approach the axis X. The Gaussian distribution, therefore, shows the most frequent values in the center of the bell, with the least frequent at the ends.
Take the case of average height of the mens between 18 and 60 years old born in a certain region. Although in this group there are people who measure 1.45 meters and others who measure 2.05 meters, most of the subjects have a height between 1.65 and 1.85 meters. The normal curve will cause these most common values to be reflected in the center of the gaussian bell.
In the same way, in addition to all the above, we cannot ignore either that there are other relevant aspects about the normal curve that are worth knowing. We are referring to the following:
-Allows not only to “model” what are social or natural phenomena but also other psychological ones.
-In the eighteenth century is where the origin of the curve or normal distribution is found. Specifically, it appeared in 1733 in an article written by the French mathematician Abraham de Moivre, who has become a benchmark in statistics due to the contributions he made on probability theory. However, after him it would be perfected by other figures such as Adrien-Maire Legendre or Johann Carl Friedrich Gauss.
-Your name as such was given years later. Specifically, it was awarded in 1875 by characters such as Francis Galton, Charles S. Peirce and Wilhem Lexis.