COMPARE AND CONTRAST QUANTITATIVE AND QUALITATIVE RESEARCH

Sc hool10

NRSE_4550_M2_LA_Introduction_to_Quantitative_Researchmodule2third.ppt

Home >Nursing homework help >COMPARE AND CONTRAST QUANTITATIVE AND QUALITATIVE RESEARCH

Chapter 8

Introduction to Quantitative Research

Research Design

Purpose of Research Design

Provides the plan or blueprint

Is the vehicle for systematically testing research questions and hypotheses

Provides the structure for maintaining the control in the study

Control

Achieved with steps taken by the researcher to hold the conditions of the study uniform and avoid or decrease the effect of intervening, extraneous, or mediating variables on the dependent variable or outcome

Avoids bias or threats to the internal validity of the study

Considerations in Quantitative Research

Objectivity in conceptualization of the research question

Type of design chosen

Accuracy

Feasibility

Control and intervention fidelity

Validity: internal and external

Objectivity in Conceptualization of the Research Question

Objectivity can be achieved from a thorough review of the literature and the development of a theoretical framework.

The literature review should be presented so that the reader can judge the objectivity of the research question.

Accuracy

Accomplished through the theoretical framework and literature review

All aspects of the study systematically and logically follow from the research question.

Feasibility

Time

Is there enough time for completion of the study?

Subject availability

Are a sufficient number of eligible subjects available?

Facility and equipment availability

Are the necessary equipment and facilities available?

Feasibility

Expense

Is money available for the projected cost?

Experience

Is the study based on the researcher’s experience and interest?

Ethics

Could subjects be harmed?

Control and Intervention Fidelity

Intervention fidelity

Ensures that every subject receiving the intervention or treatment receives the identical intervention or treatment

Intervening, Extraneous, or Mediating Variables

Variables that occur during the study that interfere with or influence the relationship between the independent and dependent variables

Intervening, Extraneous, or Mediating Variables

Intervening and mediating variables are processes that occur during the study.

Extraneous variables are subject, researcher, or environmental characteristics that might influence the dependent variable.

Controlling Extraneous Variables
Homogenous Sample

Using a homogeneous sample—similarity with respect to the extraneous variables relevant to the particular study

Using consistent data collection procedures—constancy

Controlling Extraneous Variables

Training and supervising individuals delivering interventions and collecting data—constancy and intervention fidelity

Manipulating the independent variable

Randomization

Homogeneity

Participants in the study are homogeneous or have similar extraneous variables that might affect the dependent variable

Homogeneity of the sample limits generalizability or the potential to apply the results of a study to other populations

Constancy in Data Collection

Design

Training

Delivery

Receipt

Enactment

Independent Variable (X)

The independent variable is:

The variable that the researcher hypothesizes will have an effect on the dependent variable

Usually manipulated (experimental study) but sometimes cannot be manipulated (nonexperimental)

Independent Variable (X)

The independent variable is:

Manipulated by means of a program, treatment, or intervention done to only one group in the study (experimental group)

The control group gets the standard treatment or no treatment

Dependent Variable (Y)

The dependent variable is:

A factor, trait, or condition that can exist in differing amounts or types

Not manipulated and presumed to vary with changes in the independent variable

The variable the researcher is interested in explaining

Randomization

Each subject in the study has an equal chance of being assigned to the control group or the experimental group.

Randomization assumes that any important intervening, extraneous, or mediating variable will be equally distributed between the groups, minimizing variance and decreasing selection bias.

Internal Validity

Asks whether the independent variable really made the difference or the change in the dependent variable

Established by ruling out other factors or threats as rival explanations

Threats to Internal Validity

History

An event, other than the intervention, that might have an effect on the dependent variable; the event could be either inside or outside the experimental setting

Threats to Internal Validity

Maturation

Developmental, biological, or psychological processes that operate within an individual over time. These processes are outside the experimental setting

Threats to Internal Validity

Testing

Taking the same test more than once can influence the participant’s responses the next time the test is taken

Threats to Internal Validity

Instrumentation

Changes in equipment used to make measurements or changes in observational techniques may cause measurements to vary between participants related to treatment fidelity

Threats to Internal Validity

Mortality

The loss of study subjects

Selection bias

A partiality in choosing the participants in a study

External Validity

Questions the conditions under which the findings are generalized

Deals with the ability to generalize the findings outside the study to other populations and environments

Threats to External Validity

Selection effects

What method was used to select the sample? How were subjects assigned to groups?

Reactive effects

Subjects’ responses to being studied

Hawthorne effect

Threats to External Validity

Measurement effects

A pretest may act like an intervention and influence or change the subjects’ responses

Critiquing Criteria for Quantitative Studies

Is the type of design used appropriate?

Does the researcher use the various concepts of control that are consistent with the type of design chosen?

Does the design used seem to reflect the issues of economy?

Critiquing Criteria for Quantitative Studies

Does the design used seem to flow from the proposed research question, theoretical framework, literature review, and hypothesis?

What are the threats to internal validity?

What are the controls for the threats to internal validity?

Critiquing Criteria for Quantitative Studies

What are the threats to external validity?

What are the controls for the threats to external validity?

Is the design appropriately linked to the evidence hierarchy?

Which component creates the research design in a tobacco cessation study?

College males, ages 18-23

Online, 1:1, or class sessions

Maslow’s hierarchy of needs theory

Which type of education leads to sustained cessation?

ANSWER: C

RATIONALE: Maslow’s Hierarchy of Needs theory. The research process does not need to be a sterile procedure, but rather one where the researcher develops a masterful work within the limits of a research question and the related theoretical basis. The framework that the researcher creates is the design.

To increase accuracy in the previous example, which might the new researcher consider first?

A thorough literature review

Compare only online and 1:1 sessions

Complete a pilot study with a very small sample first

Remove external variables

ANSWER: B

RATIONALE: Compare only online and 1:1 sessions. To increase accuracy, a beginning researcher may answer a question involving a few variables that will not require the use of sophisticated designs. The simplicity of a research project does not render it useless or of a lesser value for practice. A helps objectivity in conceptualization of the research question, C helps feasibility control, and D, intervention fidelity. All external variables cannot be removed, only controlled.

Which internal validity threat is suspected in the following scenario?

A college health center identifies lack of testicular self-examination among students and implements an intense summer wellness program focusing on the benefits of testicular self-examination. Afterward, a count indicates an increased number of students who do not complete testicular self-examinations

History

Maturation

Testing

Mortality

Selection bias

ANSWER: D

RATIONALE: Mortality, the loss of study subjects from the first data collection point (pretest) to the second data-collection point (posttest). If the subjects who remain in the study are not similar to those who dropped out, the results could be affected. The college community has a high rate of turnover during the summer.

Which type of research design should be used in the following scenario?

A nurse researcher is investigating the effects of yoga and blood pressure. One group of subjects is participating in a yoga class and the other group is not.

Qualitative

Correlational

Meta-analysis

Experimental

ANSWER: D

RATIONALE: Experimental designs are used to compare treatment group with control group. Qualitative designs are used when there is little or no research or literature available for the area being investigated. Correlational studies look at the relationship between or among variables. Meta-analysis involves results of multiple studies.