* Hypothesis : Is a formal statement of the expected relationships between two or more variables in a specified population? The hypothesis translates the research problem and purpose into a clear explanation or prediction of expected results or outcomes of the study.
* A clearly stated hypothesis includes the variables to be manipulated or measured, identifies the population to be examined, and indicates the proposed outcomes for the study.
* Hypothesis also influences the study design, sampling technique, data collection and analysis methods, and interpretation of findings.
* Converts the question into a statement that predicts an expected outcome
Types of hypothesis:
** Simple or complex:
* A Simple hypothesis: concerns the relationship between one independent and one dependent variable (vicariate study). In experimental studies the independent variable may be considered the cause, and the dependent variable may be considered as the effect.
* Example: there is a negative relationship between denial and reports of anxiety among post myocardial infarction patients.
* A complex hypothesis: Concerns a relationship where two or more independent variables, two or more dependent variables, or both, are examined in the same study (multivariate).
* Example: there is a positive relationship between patient perception of pain control and (a) complaints of pain and (b) requests for pain medication.
**.Null and research hypothesis
* Null hypothesis (Ho) = Statistical hypothesis; predict that no relationship exists between variables.
Usually a statement of no differences or no associations – an equality Sentence
* There will be no difference in at-home and pre-school program children on pre-social and pre-literacy tests.
Research hypothesis (H1) = Alternative hypothesis; state the expected relationship between variables.
** Non-directional and directional research hypothesis
* Non directional hypothesis: the direction of the relationship is not presented.
* Directional: the direction of the relationship is present. It should contain a predictive terms such as more than, greater than, decrease in, or positive correlation. It is the preferred type for nursing research studies. E.g. Anxiety levels are lower for preoperative hysterectomy patients who have practiced relaxation exercises than for preoperative hysterectomy patients who have not practiced relaxation exercises.