Hypothesis

 

Hypothesis

A hypothesis can be defined as a tentative explanation of the research problem, a possible outcome of the research, or an educated guess about the research outcome. Its testing is a form of inferential statistics that allows us to draw conclusions about an entire population based on a representative sample.

A research hypothesis: It can be defined as a clear, specific and predictive statement that states the possible outcome of a scientific study. The result of the research study is based on previous research studies and can be tested by scientific research. It could be understood in terms of Simple Research hypothesis and Complex Research Hypothesis. A simple research hypothesis predicts the relationship between a single independent variable and a single dependent variable. A Complex hypothesis predicts the relationship between two or more independent variables and two or more dependent variables.

Alternative hypothesis: It is usually the one which one wishes to prove. The alternative hypothesis is the other theory about the properties of the population in hypothesis testing. Typically, the alternative hypothesis states that a population parameter does not equal the null hypothesis value. In other words, there is a non-zero effect. If your sample contains sufficient evidence, we can reject the null and favor the alternative hypothesis. The alternative is often identified with H₁

 Null hypothesis: It  is the one which one wishes to disapprove. The null hypothesis is one of two mutually exclusive theories about the properties of the population in hypothesis testing. Typically, the null hypothesis states that there is no effect (i.e., the effect size equals zero). The null is often signified by H₀.

Directional hypothesis: It measures the direction of variation of two variables. This effect of one variable on the other variable can be in positive direction or in negative direction.

 Non-directional hypothesis: It  does not indicate the kind of effects but only shows the relation between two variables.

Characteristics of a Good Hypothesis:

Good hypothesis must be based on a good research question. It should be simple, specific and stated in advance.

  i) Hypothesis should be simple so that it is easily understood by everyone.

 ii) Hypothesis should be clear, specific and precise.

iii) Hypothesis should be capable of being tested.

 iv) Hypothesis should state relationship between variables. 

Some important questions

1.    Using equivalent samples, a researcher obtained a significant correlation 95 times out of 100 trials. He/ She decided to reject the null hypothesis. The alpha level would be : (1) .01 (2) .02 (3) .05 (4) .001

2.    Further, supposing the researcher computes a value of ‘t’ for testing the significance of the difference between mean achievement of the two groups and finds that it is statistically significant. What decision would be warranted on the basis of this evidence? (1) The researcher retains The Null hypothesis and the research hypothesis as well (2) The researcher rejects The Null hypothesis and retains the research hypothesis (3) The researcher rejects both the research hypothesis as well as The Null hypothesis (4) The researcher accepts The Null hypothesis with no decision on the research hypothesis

 

3.    The following example is of a hypothesis in a study undertaken at school level “School children from rural background are prone to less stress as compared to their counterpart in the urban areas”. This statement may be considered as an instance of which type of hypothesis? (1) Principal research hypothesis (2) Action research hypothesis (3) Null hypothesis (4) Directional hypothesis