The p-value of the test is not a ‘mathematical index’, it is simply a relative frequency
*Correspondencia: Dra. Carmen Carazo-Díaz. Universidad Católica San Antonio de Murcia. Avenida de los Jerónimos, 135. E-30107 Guadalupe de Maciascoque, Murcia.
E-mail: ccarazo@ucam.edu
Leading scientific journals in fields such as medicine, biology and sociology repeatedly publish articles and editorials claiming that a large percentage of doctors do not understand the basics of statistical analysis, which increases the risk of errors in interpreting data, makes them more vulnerable to misinformation and reduces the effectiveness of research. This problem extends throughout their careers and is largely due to the poor training they receive in statistics - a problem that is common in developed countries. As stated by H. Halle and S. Krauss, '90% of German university lecturers who regularly use the p-value in tests do not understand what that value actually measures'. It is important to note that the basic reasoning of statistical analysis is similar to what we do in our daily lives and that understanding the basic concepts of statistical analysis does not require any knowledge of mathematics. Contrary to what many researchers believe, the p-value of the test is not a 'mathematical index' that allows us to clearly conclude whether, for example, a drug is more effective than a placebo. The p-value of the test is simply a percentage.