A hypothesis is a probable, objective, and specific answer to a scientific question, which must be verified.
There are different types of hypotheses: the research or working hypothesis, the alternative hypothesis, the null hypothesis, or the statistical hypothesis.
However, it is possible for an investigation to have more than one hypothesis. This means that the different types of hypotheses are also related to each other. For example, a research hypothesis can act as the main hypothesis in a work, but in turn, the null, alternative and statistical hypotheses help to clarify the central hypothesis.
To understand this better, let's look at each type of hypothesis separately and its respective variants (with examples).
The research hypothesis aims to answer what is the relationship established between various variables. It is also known as a working hypothesis. It is the starting point of all scientific research.
According to its approach, it is divided into descriptive hypotheses, causal hypotheses, correlational hypotheses, or group difference hypotheses.
They limit themselves to describing the relationship between the variables under study but do not explain their causes. They anticipate the expected variable type, value, and qualities.
For example, "Crime in the city of Caracas has increased by 50% compared to 2019."
Causal hypotheses or causality hypotheses are those that propose to explain the cause-effect relationship between two or more variables. They can be explanatory or predictive.
Both explanatory and predictive hypotheses can be formulated inductively or deductively. Let's see.
Correlational or joint variation hypotheses are those that establish the degree of the mutual relationship between the variables, that is, how and to what degree one affects the other (and vice versa). In this type of hypothesis, the order of the variables does not matter.
For example, Newton's theory of gravity is a correlational hypothesis, since its statement dictates: "The greater the mass, the greater the force of attraction." Correlatively, it follows that: "The greater the attractive force, the greater the mass."
Correlational hypotheses can be negative, positive, or mixed.
Group difference hypotheses are those that anticipate the difference in the behavior of various groups. It is based on statistical comparison. Group difference hypotheses are expressed in two variants:
The null hypothesis is one that denies the relationship between two or more variables based on a sample parameter. Your statement is negative, which means that it includes a "no." It is represented by the symbol H 0. The null hypothesis is not accepted but is either rejected or not rejected.
The formulation of the null hypothesis is usually accompanied by the formulation of an alternative hypothesis that seeks to prove it false.
For example, "The muscle mass index is not associated with the sex of people."
Every null hypothesis generates an alternative hypothesis, that is, an alternative answer to the null hypothesis that purports to prove it false. It is represented by the symbol H 1 . This type of hypothesis is accepted or not accepted.
Statistical hypotheses are those that translate the hypotheses into statistical symbols. Seek to assert or define the parameters of one or more populations. Therefore, they are formulated whenever data is expected to be collected in numbers, percentages, or averages.
They are subdivided into: