Research Hypothesis

‘Hypothesis is a statement containing two or more variables that are measurable or potentially measurable and that specify how the variables are related’ (Kerlinger 1986).
Hypothesis is a tentative, intelligent guess as to the solution of the problem. It is a declarative statement that predicts the relationship between independent variables, specifying the population that will be studied. We can say that it is an educated guess.

A research hypothesis must be:
•    Testable
•    Based on sound rationale
•    Researcher  must be able to confirm or contradict the hypothesis according to evidence

Purpose and Function of Hypothesis

Hypothesis is formulated when the researcher is fully aware of the theoretical empirical background of the problem. It offers explanations for the relationships between those variables that can be empirically tested. It gives direction to an investigation. It structures the next phase in the investigation and therefore furnishes continuity to the examination of the problem.

Null Hypothesis

It states that there is no difference between groups and observed difference could be due to chance. It is represented by H0.

Simple Hypothesis

It includes one independent variable and one dependent variable. E.g. intake of fatty food predisposes to hypertension.

Complex Hypothesis

It contains more than one independent and dependent variables. E.g. Smoking and fatty food intake leads to hypertension and ischemic heart disease.

Non-Directional Hypothesis

It describes the relationship between variables but gives no direction of relation. E.g.
Cholesterol levels affect the heart.
Intravenous administration of antibiotics affects wound healing time than oral administration.

Directional Hypothesis

It not only describes the relationship between variables, but gives a definite idea about the direction of that relationship. E.g.
Increased cholesterol levels cause coronary heart disease
Intravenous administration of antibiotics decreases wound healing time than oral administration.

Operational Definition

It defines a variable according to its unique meaning within a study. It should be sufficiently detailed that another researcher may replicate the procedure or condition. It should be clarify term by explaining how they are observed or measured. Details of the tools and procedures used to obtain the measurements should be recorded as well.