Chap05 JOHN W. CRESWELL

Chapter 5 Specifying a Purpose and Research Questions or Hypotheses

Power Point Slides by Ronald J. Shope in collaboration with John W. Creswell

Key Ideas • The difference between purpose statements, statements, hypotheses, and research questions • Variables in quantitative research • Quantitative purpose statements, questions, hypotheses • Qualitative purpose statements, questions, hypotheses Educational Research 2e: Creswell

What are Purpose Statements, Research Questions, Hypotheses, and Objectives? Purpose Statement Intent Form Use

Placement

Overall Direction

Research Questions

Research Hypotheses Objectives

Raise questions to be answered

Make predictions about expectations

One or more

One or more

sentences

questions

One or more questions

One or More Objectives

Quantitative Research

Typically Quantitative Research

Quantitative and Qualitative Research End of Introduction

Quantitative and Qualitative Research

State Goals

End of the introduction, after the literature review, or in a separate section of the study

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Why are these statements and questions important? • Represent major signposts • Help identify appropriate methods • Help link intent with the results

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What We Need to Know to Design Quantitative Purpose Statements, Research Questions, and Hypotheses

• What is a variable? • What is a theory? • What elements go into these statements and questions?

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What is a Variable? A Variable (A Characteristic or Attribute)

That can be

Measured (Can be assessed on an instrument and recorded on an instrument)

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and

Varies (Can assume different values or scores for different individuals)

Examples of variables and non-variables Difficult but possibly measurable variables

Variables • • •

Leadership style Organizational control Autism

• • • •

Socialization Imagination Intuition Discrimination

Almost impossible to measure variables • Subconscious thoughts • World poverty • Stereotypes

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Categorical and Continuous measures of variables •  A categorical measure is a value of a variable assigned by the researcher into a small number of categories. (e.g. Gender) •  A continuous measure 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)

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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 2e: Creswell

The Family of Variables in Quantitative Studies Probable Cause

(X) Independent Variables Treatment Measured

Effect

(Y) Intervening Variables

(Z) Dependent Variables

•

•

Control Variables Moderating Variables

Confounding Variables Educational Research 2e: Creswell

Families of Variables • Dependent Variables: An attribute or characteristic influenced by the independent variable.

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Families of Variables • Independent Variable: An attribute or characteristic that influences or effects an outcome or dependent variable.  – Treatment Variable  – Measured Variable  – Control Variable  – Moderating Variable

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Intervening Variables • Intervening Variables (Mediating Variables): An attribute or characteristic that “stands between” the dependent and independent variables.

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Example of an Intervening Variable Step 1

Independent Variable

Dependent Variable

Example Convenient office hours

Student seeks help from faculty

for students

Step 2 Example

Step 3 Example

Independent Independent Variable Variable Convenient office hours for students

Independent Variable Convenient office hours for students

Intervening Variable Student becomes willing to take risks

Intervening Variable Student becomes willing to take risks

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Dependent Variable Student seeks help from faculty

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 dependent variable. Educational Research 2e: Creswell

Theories as Bridges Between Independent and Dependent Variables

Independent Variables

Dependent Variables

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Different Types of Explanations in quantitative research Broad Abstractions

Extensive Tests by other researchers

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

No Test

As explanation posed by the author as a hunch for why the independent variable relates to the dependent variable Educational Research 2e: Creswell

Narrow Application

Elements of purpose statement • Single sentence • “The purpose of this study . . .” • Theory • Quantitative words (e.g. “Relate,” “Compare,” “Describe”)

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Elements of purpose statement • Variables  – Independent Variable (1 st position in sentence)  – Dependent Variable (2 nd position in sentence)  – Control and/or mediating variable (3 rd position in sentence)  – Research site  – Participants

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Quantitative Research Questions • 3 types:  – Describe results to your variables  – Compare two or more groups on the independent variable in terms of the dependent variable  – Relate two or more variables

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Research Hypotheses • Three types:  – Null hypothesis  – Directional alternative hypothesis  – Non-directional alternative hypothesis

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How do You Design Qualitative Purpose Statements and Research Questions?

• Understand how these statements and questions differ from quantitative research • Understand the role of a central phenomenon in qualitative research • Understand qualitative research as an emerging process

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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?”)

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Explaining or predicting variables versus exploring or understanding a Central Phenomenon

Qualitative

Quantitative

Understanding or exploring a Central Phenomenon

Explaining or Predicting Variables X

Y

The independent variable (X) influences a dependent variable (Y)

Y

In-depth understanding of Y; external forces shape and are shaped by Y

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Two qualitative research considerations • 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

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Elements of purpose statement • Single sentence • “The purpose of this study . . . ” • Central Phenomenon • State qualitative type of design • Qualitative words (e.g. “explore,” “understand,” “discover”) • Participants • Research site

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Two Types of qualitative Research Questions: • Central question • Sub-questions • Differences between research questions and questions asked during data collection

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