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Reading
Reading
Schmidt & Brown (2021). Evidence-Based Practice for Nurses:
Chapter 4.1: How Clinical Problems Guide Research Questions
Chapter 4.2: Developing Hypotheses
Objective
Objective
Differentiate among associative, causal, simple, complex, nondirectional, directional, null, and research hypotheses
Identify independent and dependent variables
Define mediators, moderators, and confounding variables
Narrowing the Research Question
Narrowing the Research Question
Research problem
= An area of concern when there is a gap in knowledge that requires a solution
Problem statement
= A formal statement describing the problem addressed in the study
Purpose statement
= A statement indicating the aim of the study
Research question
An interrogatory statement describing the variables and population of the research study
Figure 4.1. Narrowing the Research Question
Figure 4.1. Narrowing the Research Question
The interconnected stages in the process are as follows:
Clinical practice, problem of interest, research topic, generate topics, research problem, research purpose, and research question and/or hypotheses
Generating questions leads to nonresearchable questions
Literature review is interconnected with research problem and research question and/or hypotheses
Developing Hypotheses
Developing Hypotheses
Hypotheses
= Formal statements regarding the expected or predicted relationship among two or more variables
Types of Hypotheses
Types of Hypotheses
Associative vs. Causal Hypotheses
Associative relationship
= A type of relationship such that when one variable changes, the other variable changes
covary
= When change in one variable is associated with change in another variable
Causal relationship
= When on variable determines the presence or change in another variable
Simple vs. Complex Hypotheses
Simply hypothesis
= A hypothesis describing the relationship between only two variables
Complex hypothesis
= A hypothesis describing the relationships among three or more variables
Nondirectional vs. Directional Hypotheses
Nondirectional hypothesis
= Statement of the relationship between two variables that does not predict the direction of the relationship
Directional hypothesis
= Statement describing the direction of a relationship between two or move variables
Null hypotheses vs. Research Hypotheses
Null hypothesis
= A hypothesis stating that there is no relationship between the variables; the statistical hypothesis
Research hypothesis
= A hypothesis indicating that a relationship between two or more variables exists
Variable
Variable
To understand hypothesis testing, it is important to understand the nature of variables.
Variable
May be phenomena that can be directly measured, such as pulse rate, blood pressure, respiratory rate, red blood cell count, antibody titer, thyroid-stimulating hormone, or salivary cortisol levels
May be qualities, properties, or characteristics of people, groups, or objects, such as sociodemographic characteristics, intelligence, social support, and self-esteem
Measured indirectly using questionnaires and scales
May be derived from abstract concepts, such as depression, anxiety, grieving, and quality of live, which require some indirect type of measurement
Variables are categorized as independent, dependent, and confounding variables
Independent variable
= Variable that influences the dependent variable or outcome; intervention, innovation, or treatment that is manipulated by the researcher; X variable
Dependent variable
= Outcome or variable that is influenced by the independent variable; Y variable
Confounding variables
= Factors that interfere with the relationship between the independent and dependent variables; extraneous variables; Z variable
Extraneous variables
= Factors that interfere with the relationship between the independent and dependent variables; confounding variables; Z variable
Mediators
= Extraneous variables that come between the independent and dependent variables
Moderators
= Extraneous variables that affect the relationship between the independent and dependent variables
Example of Moderation Effects
Example of Moderation Effects
Genetic influence on resilience to potentially traumatic events
Figure taken from p. 109
Additional Resources
Additional Resources
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