This document discusses hypotheses in research studies. It defines a hypothesis and explains their purposes, including guiding research design and statistical analysis. Hypotheses can be classified in various ways, such as simple vs complex, directional vs nondirectional, and causal vs associative. The null hypothesis predicts no relationship while the research hypothesis states an expected relationship. Guidelines are provided for developing testable hypotheses and critiquing them in research reports.

1. Hypotheses
 Introduction
 Hypotheses Overview
 Purposes of Hypotheses
 Sources or Rationale for Hypotheses
 Classifications of Hypotheses
 Simple and Complex Hypotheses
 Nondirectional and Directional Research Hypotheses
 Causal and Associative Research Hypotheses
 Null and Research Hypotheses
 Developing Hypotheses
 Hypothesis Format
 Hypotheses and Theory Testing
 Critiquing Hypotheses

2. Learning objectives :
 Describe the role of hypotheses in research studies.
 Compare classifications of hypotheses.
 Describe the considerations when developing hypotheses.

3. You wonder why the traffic is moving so slowly. You start thinking
of possible reasons. There may have been an accident up ahead.
Or may be a car has stalled and people must switch lanes to get
past the stalled car. Maybe road construction is to blame. The next
thought that comes to mind is there may be a police officer parked
on the side of the road just waiting for speeders. Suddenly, you see
flashing lights and hear an ambulance siren. Then you see two
crumpled cars and people standing around them. You are now
aware that an accident is the cause of the traffic slowdown. The
hunches you had about the reasons for the slow traffic could be
considered hypotheses.
Introduction

4. In scientific research, hypotheses are intelligent guesses that assist
the researcher in seeking the solution to a problem.
Kerlinger (1986) has defined a hypothesis as a “conjectural
statement of the relations between two or more variables” .
Polit and Beck (2012) presented a similar definition by calling a
hypothesis
a “statement of the researcher’s expectations about relationships
between study variables” .
we define a hypothesis as a statement of the predicted relationship
between two or more variables.
Hypotheses Overview

5. Hypotheses serve several purposes in research studies
 • They lend objectivity to scientific investigations by
pinpointing a specific part of a theory to be tested.
 • Through hypotheses, theoretical propositions can be tested
in the real world.
 • Hypotheses also guide the research design and dictate the
type of statistical analysis to be used with the data.
 • hypotheses provide the reader with an understanding of the
researcher’s expectations about the study before data collection
begins.
Purposes of Hypotheses:

6. Hypotheses are not wild guesses or shots in the dark. The
researcher should be able to state the source or rationale for each
hypothesis. This source or rationale for the hypothesis may come
from a theory, literature review of prior studies, or personal
experience.
Hypotheses for nursing research studies can also be derived from
the findings of other studies. The researcher may test the
assumptions of another study, or test a hypothesis based on the
findings of another study.
Sources or Rationale for Hypotheses

7. Hypotheses can be categorized as simple hypotheses or complex
hypotheses. They can also be classified as research hypotheses or
null hypotheses. Research hypotheses can be further divided into
nondirectional and directional hypotheses, and causal and
associative hypotheses.
Classifications of Hypotheses

8. A simple hypothesis concerns the relationship between one
independent variable and one dependent variable.
in experimental studies the independent variable may be
considered as the cause, or reason , and the dependent variable
may be considered the effect.
A complex hypothesis concerns a relationship in which two or
more independent variables, or two or more dependent variables,
or both, are being examined in the same study.
Simple and Complex Hypotheses

9. In a nondirectional research hypothesis, the researcher merely
predicts that a relationship exists. When a study is not based on a
theory or the findings of related studies are contradictory, the
investigator may decide to use a nondirectional hypothesis.
In the directional research hypothesis, the researcher predicts the
type of relationship that is expected.
Nondirectional and Directional Research
Hypotheses

10. A causal research hypothesis predicts that the independent variable
will cause something to occur to the dependent variable; the effect
on the dependent variable is a direct result of the independent
variable.
An associative research hypothesis predicts that there will be a
relationship between the variables.
Causal and Associative Research
Hypotheses

11. null hypothesis (H0) predicts that no relationship exists between
variables, and it is the null hypothesis that is subjected to statistical
analysis.
A research hypothesis or alternative hypothesis (H1) states the
expected relationship between variables.
Other names for the research hypothesis are scientific, substantive,
and theoretical.
Null and Research Hypotheses

12. A hypothesis should:
1. be written in a declarative sentence.
2. be written in the present tense.
3. contain the population.
4. contain the variables.
5. reflect the problem statement, purpose statement, or research question.
6. be empirically testable.
Developing Hypotheses

13. Research questions that examine more than one variable are
usually written in the form of a correlational statement or
comparative statement. The same holds true for hypotheses.
The issue of correlations and comparisons becomes very
important when the data are submitted for statistical analysis.
Hypothesis Format

14. It is important at this point to mention hypothesis testing and its
relation to theory. A hypothesis usually tests only one proposition
from a theory, not an entire theory. Hypotheses are never proved
or disproved. Novice researchers can be spotted easily if they
discuss trying to prove their hypotheses. Remember, neither
theories nor hypotheses are proved.
Hypotheses and Theory Testing

15. First, the evaluator of a research report determines if the report
contains a hypothesis or hypotheses. Optimally, a section
heading clearly labels the hypotheses. If the study contains no
hypotheses, a determination should be made as to whether or
not the study is appropriate for hypothesis testing.
Critiquing Hypotheses

16. 1. Does the study contain a hypothesis or hypotheses?
2. Is each hypothesis clearly worded and concise?
3. Is the hypothesis written in a declarative sentence?
4. Is each hypothesis directly tied to the study problem?
5. If there is a clearly identified study framework, is each hypothesis derived
from this framework?
6. Does each hypothesis contain the population and at least two variables?
7. Is each hypothesis stated as a directional research hypothesis? If not, is the
rationale given for the type of hypothesis that is stated?
8. Is it apparent that each hypothesis can be empirically tested?
9. Does each hypothesis contain only one prediction?
Guidelines for Critiquing
Hypotheses and Research Questions