Table of Contents

## What is Hypothesis?

A hypothesis is a proposed explanation for a phenomenon. A scientific hypothesis must be testable, meaning that it can be verified by empirical evidence.

## Types of Hypothesis

There are four types of hypotheses: null, alternative, research, and explanatory.

Null hypotheses are statements that there is no relationship between two variables. Alternative hypotheses are statements that there is a relationship between two variables. Research hypotheses are hypotheses that are tested in research studies. Explanatory hypotheses are hypotheses that explain relationships between variables.

## Alternative Hypothesis

Alternative hypotheses are important in scientific inquiry because they allow scientists to explore all possible explanations for an observed phenomenon. In the context of scientific research, the alternative hypothesis is the hypothesis that is tested when the researcher is trying to disprove the null hypothesis. The alternative hypothesis is also sometimes known as the research hypothesis. The alternative hypothesis is always formulated in such a way that it is capable of being tested.

The alternative hypothesis is important because it allows researchers to explore all possible explanations for an observed phenomenon. If the alternative hypothesis is not testable, then it cannot be used to guide scientific research. The alternative hypothesis is also important because it can help researchers to develop new hypotheses.

The alternative hypothesis is also important because it can help researchers to identify potential flaws in their research. If the alternative hypothesis is not supported by the data, then the researchers may need to reevaluate their research methodology. The alternative hypothesis can also help researchers to identify areas where more research is needed.

## Examples of Alternative Hypothesis

There are many possible alternative hypotheses that could be tested in a research study. Some examples include:

The null hypothesis is true, but the alternative hypothesis is false.

The alternative hypothesis is true, but the null hypothesis is false.

The null hypothesis is false, but the alternative hypothesis is true.

The alternative hypothesis is true for some groups but not for others.

The alternative hypothesis is true in the present, but not in the past or future.

## Difference Between The Null Hypothesis And Alternative Hypothesis

The null hypothesis is the hypothesis that there is no difference between the groups being studied. The alternative hypothesis is the hypothesis that there is a difference between the groups being studied.

## Types

In the case of a scalar parameter, there are four principal types of alternative hypothesis:

*Point*. Point alternative hypotheses occur when the hypothesis test is framed so that the population distribution under the alternative hypothesis is a fully defined distribution, with no unknown parameters; such hypotheses are usually of no practical interest but are fundamental to theoretical considerations of statistical inference and are the basis of the neyman persona lemma.*One-tailed directional*. A one-tailed directional alternative hypothesis is concerned with the region of rejection for only one tail of the sampling distribution.*Two-tailed directional*. A two-tailed directional alternative hypothesis is concerned with both regions of rejection of the sampling distribution.*Non-directional*. A non-directional alternative hypothesis is not concerned with either region of rejection, but, rather, it is only concerned that null hypothesis is not true.