1. Specifying a Purpose, Research Questions or Hypothesis
Chapter 5
Specifying a Purpose, Research Questions or Hypothesis
Educational Research by John W. Creswell. Copyright © 2002 by Pearson Education. All rights reserved.

2. Key Ideas
The difference between purpose statements, hypotheses, and research questions
Variables in quantitative research
Qualitative research considerations
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

3. Purpose Statements, Research Questions, Research Hypotheses, Research Objectives
Purpose statements: a declarative statement that advances the overall direction or focus for the study.
Research Questions: Interrogative statements that narrow the purpose statement to specific questions that researchers seek to answer in their study.
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

4. Purpose Statements, Research Questions, Research Hypotheses, Research Objectives
Research Hypotheses: Declarative statements in quantitative research in which the investigator makes a prediction or conjecture about the outcomes relationship.
Research Objective: A statement of intent for the study that specifies specific goals that the investigator plans to achieve in a study.
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

5. Distinguishing among various forms of direction in research
Purpose
Statement
Research
Questions
Hypothesis
Research
Objectives
Overall
Direction
Intent
Raise questions
to be answered
Make predictions
about expectations
State Goals
Form
One or more
sentences
One or More
Objectives
One or more
questions
One or more
questions
Use
Quantitative
and
Qualitative
Research
Quantitative
and
Qualitative
Research
Quantitative
Research
Typically
Quantitative
Research
End of the introduction, after the literature
review, or in a separate section of the study
End of
Introduction
Placement
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

6. Definition of a Variable
(A Characteristic or Attribute)
Can be
and
Measured
Varies
(Can be assessed
on an instrument
and recorded on
an instrument)
(Can assume
different values or
scores for
different
individuals)
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

7. Variables and Constructs
A Variable is an attribute or characteristic stated in a specific or applied way
A Construct is an attribute or characteristic expressed in an abstract, general way.
Construct Student Achievement
Variable Grade Point Average
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

8. Categorical and Continuous Scores
A categorical score is a value of a variable assigned by the researcher into a small number of categories. (e.g. Gender)
A continuous variable is the value of a variable assigned by the researcher to a point along a continuum of scores, from low to high. (e.g. Age)
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

9. Families of Variables
Independent Variable: An attribute or characteristic that influences or effects an outcome of the independent variable.
Treatment Variable
Measured Variable
Control Variables
Moderating Variables
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

10. Families of Variables
Intervening Variables (Mediating Variables): An attribute or characteristic that “stands between” the dependent and independent variables.
Dependent Variables: An attribute or characteristic influenced by the independent variable.
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

11. Families of Variables
Confounding Variables (Spurious Variables): Attributes or characteristics that the researcher cannot directly measure because their effects cannot be easily separated from the other variables, even though they may influence the relationship between the independent and the independent variable.
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

12. The Family of Variables in Quantitative Studies
Probable
Cause
Effect
Independent
Variables
Treatment
Measured
Intervening
Variables
Dependent
Variables
Control
Variables
Confounding
Variables
Moderating
Variables
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

13. Intervening Variables “Stand Between” Independent and Dependent Variables
Step 1
Dependent
Variable
Example
Convenient office hours
for students
Student seeks help from faculty
Independent
Variable
Intervening
Variable
Independent
Variable
Step 2
Convenient office hours
for students
Student becomes willing
to take risks
Example
Independent
Variable
Intervening
Variable
Step 3
Dependent
Variable
Convenient office hours
for students
Student becomes willing
to take risks
Student seeks help from faculty
Example
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

14. Theories as Bridges Between Independent and Dependent Variables
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

15. Different Types of Explanations in Quantitative Research
Extensive Tests by
other researchers
Broad
Abstractions
As a formal theory that is expressed by connected
hypotheses and variables identified by authors
As a conceptual framework often expressed as a
visual model by other authors for relationship
As a theoretical rationale posed by other authors
based on studies for relationship
As explanation posed by the author as a hunch for
why the independent variable relates to the
dependent variable
No Test
Narrow
Application
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

16. Whether Variables Prove Probable Cause
Probable causation: The researchers attempt to establish a likely cause/effect relationship between variables rather than prove the relationship.
Control is vital: Control means that the researcher attempts to study all factors that might help explain the relationship between an independent and dependent variable.
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

17. Four Types of Probable Causality
X = independent variable Y = dependent variable
1. Time: Close in time, not distant
X-Y, not X Y
2. Space: Close in distance, not distant
X-Y, not X Y
3. Variation: One goes up, the other down
X Y, not X Y
3. Multiple Causes: Multiple independent variables
influence the dependent variable X Y
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

18. Quantitative - more closed
Differences between quantitative and qualitative purpose statements and research questions
Quantitative - more closed
1. Probable cause/Effect (“Why did it happen?”)
2. Use of theories (Why did it happen in view of an explanation or theory?”
3. Assessing differences and magnitude
“How much happened?”
“How many times did it happen?
What were the differences among groups in what happened?
Qualitative - more open-ended
1. Descriptive (“What happened?”)
2. Interpretive (“What was the meaning to people of what happened?”)
3. Process-oriented (“What happened over time?”)
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

19. Quantitative Qualitative
How researchers explain or predict variables versus exploring or understanding a Central Phenomenon
Quantitative
Explaining or Predicting Variables
Qualitative
Understanding or exploring a Central Phenomenon
X Y Y
The independent variable (X)
influences a dependent
variable (Y)
In-depth understanding of Y;
external forces shape and are
shaped by Y
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.

20. Qualitative Research Considerations
More open-ended
The direction of the study is focused on how to best learn from the participants
The focus of the research is around a Central Phenomenon which is an issue or a process the researcher would like to study.
Qualitative research is built on an emerging design
Educational Research by John W. Creswell. Copyright ©2002 by Pearson Education. All rights reserved.