Copyright © 2012 Wolters Kluwer Health Lippincott Williams

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams
& Wilkins
Chapter 9
Quantitative Research Design
*
& Wilkins
Question
Tell whether the following statement is true or false:
Many qualitative nursing studies aim to elucidate cause-and-
effect relationships.
& Wilkins
Answer
False

Many quantitative not qualitative nursing studies aim to
elucidate cause-and-effect relationships.
& Wilkins
Question
Counterfactual is what would have happened to the same people
simultaneously exposed and not exposed to the causal factor.
& Wilkins
Answer
True
Counterfactual is what would have happened to the same people
simultaneously exposed and not exposed to the causal factor.
& Wilkins
The Counterfactual MethodThe counterfactual is what would
have happened to the same people simultaneously exposed and
not exposed to the causal factor.Effect represents the difference
between the two.
*

& Wilkins
CausalityThe counterfactual methodCriteria for causality—
Lazarsfeld (1955)
1. Temporal
2. Empirical relationship
3. Relationship cannot be explained as
being caused by a third variable
*
& Wilkins
Experiments or Randomized Controlled Trial Properties
Manipulation
Control
Randomization
*
& Wilkins
ManipulationDoing something to study

participantsExperimenter manipulates the independent variable
by administering a treatment (intervention) to some subjects and
withholding it from others, or by administering some other
treatment.
*
& Wilkins
Control GroupResearchers can expose the control group to
various conditions:
– No treatment
– Alternative treatment
– Placebo
– Standard treatment
– Different doses of the treatment
– Wait list
*
& Wilkins
Randomization (Random Assignment or Random
Allocation)Involves placing subjects into treatment conditions
at randomApproximates the ideal—but impossible—
counterfactual of having the same people in multiple treatment
groups simultaneouslyBasic randomization

*
& Wilkins
Question
Some studies involve patient-centered interventions that are
tailored to meet individual needs or characteristics.
& Wilkins
Answer
True
Everyone in the experimental group usually gets the same
intervention as delineated in formal protocols, but some studies
involve patient-centered interventions (PCIs) that are tailored to
meet individual needs or characteristics.
& Wilkins
Small Table of Random Digits
& Wilkins
Example of Random Assignment Procedure

& Wilkins
StratificationDivided into groups before randomizedPermuted
block randomization
& Wilkins
BlindingSingle-blind studiesDouble-blind studies
& Wilkins
RandomizationClusterPartially randomized patient preference
designRandomized consent design
& Wilkins
Experimental DesignsAfter-only (posttest-only) designBefore–
after (pretest–posttest) designFactorial designCrossover
(repeated measures) design
*
& Wilkins

Symbolic Representation of a Pretest–Posttest Experimental
Design
R O1 X O2
R O1 O2
R = Randomization
O = An observation or measurement
X = An intervention
*
& Wilkins
Factorial DesignsTwo or more variables are manipulated
simultaneously.Test both main effects and interaction
effectsRandomized block designCrossover design
*
& Wilkins
Quasi-Experimental and
Preexperimental Designs

Nonequivalent control group pretest–posttest design (quasi-
experimental)
O1 X O2
O1 O2
Nonequivalent control group posttest-only design
(preexperimental)
X O1
O1
One group pretest-posttest design (preexperimental)
O1 X O2
*
& Wilkins

Quasi-Experimental Designs
Time series designNonequivalent control group
before–after
design
*
& Wilkins
Time Series Design
O1 O2 O3 O4 X O5 O6 O7 O8
*
& Wilkins
Other Quasi-Experimental DesignsQuasi-experimental dose-
response analysisQuasi-experimental (nonrandomized) arms of a
PRPP randomization design

*
& Wilkins
Nonexperimental/Observational ResearchDescriptive
researchCorrelational studies
*
& Wilkins
Designs of Correlational StudiesRetrospective (case-control)
designProspective (cohort) designsNatural experimentsPath
analytic studies
*
& Wilkins
Descriptive StudiesPrevalence studiesIncidence studies
*

Copyright © 2012 Wolters Kluwer Health Lippincott Williams

Recommended

Recommended

More Related Content

More from CicelyBourqueju

More from CicelyBourqueju (20)

Copyright © 2012 Wolters Kluwer Health Lippincott Williams