4. Lecture objectives
List and describe the basic types of
research study designs
List and describe the types of
methods used in each research
design
5. Lecture objectives
List and describe the basic types of
research study designs
List and describe the types of
methods used in each research
design
Match the appropriate study
design to a research question
6. Research Designs
Consumer or User of Clinical Research in making
clinical decisions
Conducting Clinical Research to produce new
knowledge or applications
7. The type of study design
depends on what you are
trying to find out…or, the
research question dictates
the study design
So…
What kind of designs are
there?
8. The taxonomy of study
designs
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
9. The taxonomy of study
designs
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
10. The taxonomy of study
designs
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
11. The taxonomy of study
designs
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
12. The taxonomy of study
designs
Chapter 14
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
13. The taxonomy of study
designs
Chapter 14
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
Also addressed
in Chapter 15
14. The taxonomy of study
designs
Chapter 14
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
Also addressed
in Chapter 15
15. The taxonomy of study
designs
Chapter 14
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
Also addressed
in Chapter 15
16. The taxonomy of study
designs
Chapters
Chapter 14 10,11, and 13
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
Also addressed
in Chapter 15
17. The taxonomy of study
designs
Chapters
Chapter 14 10,11, and 13
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
Chapter 10
Also addressed
in Chapter 15
18. The taxonomy of study
designs
Chapters
Chapter 14 10,11, and 13
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
Chapter 10 Chapter 11
Also addressed
in Chapter 15
19. The taxonomy of study
designs
Chapters
Chapter 14 10,11, and 13
All studies
Descriptive Analytic
Surveys/ Qualitative Case Reports/ Experimental Quasi- Non-
Questionnaires Research Case Series Experimental Experimental/
Observational
Chapter 10 Chapter 11 Chapter 13
(Exploratory)
Also addressed
in Chapter 15
20. To Understand a Topic of
Interest, usually a series of
studies are needed:
Descriptive Studies
Observational
Analytic
Exploratory Studies
Observational and Analytical
Identifies relationships and predictions
Experimental Studies
To determine cause and effect relationships
21. To Understand an Topic of Interest
We Need A Series of Studies: First
we need…
Descriptive Studies
Describe the characteristics of a group of individuals,
phenomenon, events or behaviors of interest
Observational (not manipulating)
Examples:
What are the characteristics of adolescents with ACL injuries?
What is the “normal” strength of healthy individuals through
the life span? (normative study)
Eg, How does strength change as an individual matures and
then ages?
What is the “natural history” of a disease?
Provides the basic information needed to classify individuals
or groups
22. To Understand an Area We
Need A Series of Studies,
Second we need..
Exploratory Research
Investigates relationships among 2+ factors
human attributes, environmental characterisitics)
The factors of interest are observed as they naturally occur
to see how they inter-relate (factors are not manipulated)
Eg, What is the relationship between SAT scores and college
GPA at the end of the 1st yr of college? At college
graduation?
Eg, What factors in the application to graduate school predict
the best graduate school outcome?
Correlational studies
Predictive studies
25. In Exploratory research designs…
No manipulation of variables
Tests relationships between variables
26. In Exploratory research designs…
No manipulation of variables
Tests relationships between variables
Used to predict effect of one variable on another
27. In Exploratory research designs…
No manipulation of variables
Tests relationships between variables
Used to predict effect of one variable on another
Time . . . . what happens to variables over time?
o Prospective
o Retrospective
o Cross-sectional
29. To Understand an Area of interest We
Need A Series of Studies, lastly we
need a series of…
Experimental Studies
Evaluate cause and effect
Researcher manipulates certain variables to
determine what the effect is on other variables
Often referred to as Clinical Trials or
Randomized Controlled Trials (RCTs)
o Used to test the effectiveness of various
therapies or treatments (interventions)
o Compares groups
o Between group trials
o Within group trials
34. What are the primary differences
between descriptive and analytic
designs?
35. What are the primary differences
between descriptive and analytic
designs?
Descriptive
o Attempts to give us a
picture of what is
going on in a
population
o Identify prevalence or
incidence of disease or
condition
o Understand the
experiences, attitudes,
social norms, and/or
beliefs of a population
36. What are the primary differences
between descriptive and analytic
designs?
Descriptive Analytic
o Attempts to give us a
picture of what is
going on in a
population
o Identify prevalence or
incidence of disease or
condition
o Understand the
experiences, attitudes,
social norms, and/or
beliefs of a population
37. What are the primary differences
between descriptive and analytic
designs?
Descriptive Analytic
o Attempts to give us a o Attempts to quantify
picture of what is relationships
going on in a
population
o Identify prevalence or
incidence of disease or
condition
o Understand the
experiences, attitudes,
social norms, and/or
beliefs of a population
38. What are the primary differences
between descriptive and analytic
designs?
Descriptive Analytic
o Attempts to give us a o Attempts to quantify
picture of what is relationships
going on in a o Used to explore
population associations between
o Identify prevalence or variables
incidence of disease or
condition
o Understand the
experiences, attitudes,
social norms, and/or
beliefs of a population
39. What are the primary differences
between descriptive and analytic
designs?
Descriptive Analytic
o Attempts to give us a o Attempts to quantify
picture of what is relationships
going on in a o Used to explore
population associations between
o Identify prevalence or variables
incidence of disease or o Used to examine effect
condition of an intervention on an
o Understand the outcome
experiences, attitudes,
social norms, and/or
beliefs of a population
40. What are the primary differences
between descriptive and analytic
designs?
Descriptive Analytic
o Attempts to give us a o Attempts to quantify
picture of what is relationships
going on in a o Used to explore
population associations between
o Identify prevalence or variables
incidence of disease or o Used to examine effect
condition of an intervention on an
o Understand the outcome
experiences, attitudes, o Used to examine effect
social norms, and/or of an exposure on an
beliefs of a population outcome
41. Qualitative v. Quantitative Research
Methods
Describes the type of data that is collected
Quantitative research collects…
Numerical data
Characterisitics or attributes of individiuals are measured
42. Qualitative v. Quantitative Research
Methods
Describes the type of data that is collected
Quantitative research collects…
Numerical data
Characterisitics or attributes of individiuals are measured
Qualitative research collects
Narrative data
Words of the subjects in Interview or Focus Group:
Description of the subject of interest “lived experiences”
Helps us to understand complex social phenomenon
43. Qualitative v. Quantitative Research
Methods
Describes the type of data that is collected
Quantitative research collects…
Numerical data
Characterisitics or attributes of individiuals are measured
Qualitative research collects
Narrative data
Words of the subjects in Interview or Focus Group:
Description of the subject of interest “lived experiences”
Helps us to understand complex social phenomenon
Mixed Methods
Qualitative and quantitative data
46. Experimental Research
Designs: Terms you must
Variables or Constructs
Attributes or characteristics of the thing that is
being studied
Variables: can be directly measured
Constructs: can not be directly measured
Examples:
Joint range of motion?
Muscle strength?
Obesity?
Intelligence?
Operational Definitions
48. Variables:
Dependent variable…
What you are trying to learn about or explain
What you measure
What is expected to change or vary in response to
the IV
The presumed effect
49. Variables:
Dependent variable…
What you are trying to learn about or explain
What you measure
What is expected to change or vary in response to
the IV
The presumed effect
Independent variable
What you manipulate to see how it effects the
dependent variable
The factor that you hypothesize influences or
causes the thing you are interested
The presumed cause
55. Many other experimental designs
exist and may better suit certain research
questions.
Post-test only randomized designs
56. Many other experimental designs
exist and may better suit certain research
questions.
Post-test only randomized designs
Multi-factorial designs
o Two-way (2 independent variables)
o Three-way (3 independent variables)
57. Many other experimental designs
exist and may better suit certain research
questions.
Post-test only randomized designs
Multi-factorial designs
o Two-way (2 independent variables)
o Three-way (3 independent variables)
Repeated measures designs (within-subjects)
58. Many other experimental designs
exist and may better suit certain research
questions.
Post-test only randomized designs
Multi-factorial designs
o Two-way (2 independent variables)
o Three-way (3 independent variables)
Repeated measures designs (within-subjects)
Cross-over designs
59. Many other experimental designs
exist and may better suit certain research
questions.
Post-test only randomized designs
Multi-factorial designs
o Two-way (2 independent variables)
o Three-way (3 independent variables)
Repeated measures designs (within-subjects)
Cross-over designs
See Chapter 10 for more experimental designs
62. Quasi-experimental designs are
often excellent alternatives to true
experiments.
Very similar in structure to experimental designs
Degree of control is reduced
63. Quasi-experimental designs are
often excellent alternatives to true
experiments.
Very similar in structure to experimental designs
Degree of control is reduced
Lack random assignment to groups
64. Quasi-experimental designs are
often excellent alternatives to true
experiments.
Very similar in structure to experimental designs
Degree of control is reduced
Lack random assignment to groups
or
65. Quasi-experimental designs are
often excellent alternatives to true
experiments.
Very similar in structure to experimental designs
Degree of control is reduced
Lack random assignment to groups
or
Lack comparison groups all together
66. Quasi-experimental designs are
often excellent alternatives to true
experiments.
Very similar in structure to experimental designs
Degree of control is reduced
Lack random assignment to groups
or
Lack comparison groups all together
Again… many, many different forms exist
77. Non-Experimental designs…
more
Correlational Studies
o Extent to which a variable moves in the same or
opposite direction with another variable
o Must interpret strong correlations with caution
o Correlation does not imply causation
78. Non-Experimental designs…
more
Correlational Studies
o Extent to which a variable moves in the same or
opposite direction with another variable
o Must interpret strong correlations with caution
o Correlation does not imply causation
79. Non-Experimental designs…
more
Correlational Studies
o Extent to which a variable moves in the same or
opposite direction with another variable
o Must interpret strong correlations with caution
o Correlation does not imply causation
Prediction Studies
o Designed to predict an outcome
o Used to develop models for clinical decision
making
o Use multiple regression analysis to establish
Notas do Editor
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research question- interventions therapies\npreventions\nprognosis\netiology- cause of the condition and risk factors(characteristics that make it more likely that they develope a condition) of condition\ndisgnosis\n
descriptive - observational characteristics, traits of individuals events behaviors phenomenon that you’re interested in\nexploration-observational correlational regression\nexperimental- qusi- exp studies, the study should be controlled and randomized (helps eliminate bias)\nBias-Systematic error that affects results\n
descriptive - observational characteristics, traits of individuals events behaviors phenomenon that you’re interested in\nexploration-observational correlational regression\nexperimental- qusi- exp studies, the study should be controlled and randomized (helps eliminate bias)\nBias-Systematic error that affects results\n
descriptive - observational characteristics, traits of individuals events behaviors phenomenon that you’re interested in\nexploration-observational correlational regression\nexperimental- qusi- exp studies, the study should be controlled and randomized (helps eliminate bias)\nBias-Systematic error that affects results\n
descriptive - observational characteristics, traits of individuals events behaviors phenomenon that you’re interested in\nexploration-observational correlational regression\nexperimental- qusi- exp studies, the study should be controlled and randomized (helps eliminate bias)\nBias-Systematic error that affects results\n
descriptive - observational characteristics, traits of individuals events behaviors phenomenon that you’re interested in\nexploration-observational correlational regression\nexperimental- qusi- exp studies, the study should be controlled and randomized (helps eliminate bias)\nBias-Systematic error that affects results\n
descriptive - observational characteristics, traits of individuals events behaviors phenomenon that you’re interested in\nexploration-observational correlational regression\nexperimental- qusi- exp studies, the study should be controlled and randomized (helps eliminate bias)\nBias-Systematic error that affects results\n
descriptive - observational characteristics, traits of individuals events behaviors phenomenon that you’re interested in\nexploration-observational correlational regression\nexperimental- qusi- exp studies, the study should be controlled and randomized (helps eliminate bias)\nBias-Systematic error that affects results\n
descriptive - observational characteristics, traits of individuals events behaviors phenomenon that you’re interested in\nexploration-observational correlational regression\nexperimental- qusi- exp studies, the study should be controlled and randomized (helps eliminate bias)\nBias-Systematic error that affects results\n
descriptive - observational characteristics, traits of individuals events behaviors phenomenon that you’re interested in\nexploration-observational correlational regression\nexperimental- qusi- exp studies, the study should be controlled and randomized (helps eliminate bias)\nBias-Systematic error that affects results\n
descriptive - observational characteristics, traits of individuals events behaviors phenomenon that you’re interested in\nexploration-observational correlational regression\nexperimental- qusi- exp studies, the study should be controlled and randomized (helps eliminate bias)\nBias-Systematic error that affects results\n
descriptive - observational characteristics, traits of individuals events behaviors phenomenon that you’re interested in\nexploration-observational correlational regression\nexperimental- qusi- exp studies, the study should be controlled and randomized (helps eliminate bias)\nBias-Systematic error that affects results\n
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: identifies association but cannot determine cause and effect\n
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Characterisitics or attributes of individiuals are measured\n Variables: observable concepts that can be measured directly\n Eg, joint range of motion; muscle strength; pain\n Constructs: non-observable concepts that must be measured indirectly\n Eg, IQ\n
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An independent variable is the variable you have control over, what you can choose and manipulate. It is usually what you think will affect the dependent variable. In some cases, you may not be able to manipulate the independent variable. It may be something that is already there and is fixed, something you would like to evaluate with respect to how it affects something else, the dependent variable like color, kind, time. \nExample: You are interested in how stress affects heart rate in humans. Your independent variable would be the stress and the dependent variable would be the heart rate. You can directly manipulate stress levels in your human subjects and measure how those stress levels change heart rate.\n
An independent variable is the variable you have control over, what you can choose and manipulate. It is usually what you think will affect the dependent variable. In some cases, you may not be able to manipulate the independent variable. It may be something that is already there and is fixed, something you would like to evaluate with respect to how it affects something else, the dependent variable like color, kind, time. \nExample: You are interested in how stress affects heart rate in humans. Your independent variable would be the stress and the dependent variable would be the heart rate. You can directly manipulate stress levels in your human subjects and measure how those stress levels change heart rate.\n
