1. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Research Foundations of Nursing Research Fifth Edition Chapter 9 Quantitative Research Designs Rose Marie Nieswiadomy

2. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Dimensions of research design in quantitative studies Will there be an intervention? What types of comparisons will be made? How will extraneous variables be controlled? When and how many times will data be controlled? In what setting will the study take place?

3. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Dimensions of research design in quantitative studies DimensionDesign Control over independent variables Experimental Quasi-experimental Pre-experimental None-experimental Type of group comparison Between-subjects Within-subjects TimeframsCross-sectional longitudinal Observance of IV and DV Retrospective Prospective SettingNaturalistic Laboratory

4. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Exploratory studies Conducted when little is known about the phenomena of interest. For new or undiscovered topics In exploratory studies there is a interest in examining the qualitative aspect of the data rather than the quantitative aspects. May not have a specific research question

5. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Exploratory studies Can be challenging because there are few guidelines to follow and the goals may change Makes use of creativity and serendipity. e.g. the needs of family members in intensive care waiting rooms. Usually focused on the “what,” not the “why”

6. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Descriptive Studies It is similar to exploratory studies …however, they are different in the amount of information that is available about the variables. Conducted when enough information exists to examine relationships between variables. Presents a picture with specific details of the situation or behavior Requires a focused research question/topic Focuses on “how” and “who” questions Is necessary for good explanatory research

7. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Explanatory Studies Usually experimental in nature. Helps provide explanations for the relationships among phenomena. The researcher can exercise some control over the research and manipulate one or more variables. Focuses on “why”, or the reason a situation or behavior occurs Builds on exploratory and descriptive research, and other explanatory research Uses theory Much of the research published in journals is explanatory

8. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Experimental design Concerns with cause and effect. Involves manipulation or control of the independent variable. An experiment is manipulating an independent variable to see how it affects a dependent variable while controlling the effects of extraneous variables. Note …..control is difficult when conducted research on human beings.

9. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Experimental design Control of extraneous variables is typically achieved by the use of a second group of subjects, known as the control group. This is a group whose subjects have not been exposed to the change in the independent variable. The experimental group is the group that has been exposed to a change in the independent variable

10. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Validity of experimental designs Extraneous (confounding/intervening) variables: those variables that the researcher is not able to control or does not choose to control and which may influence the results of a study. Internal validity: concerns the degree to which changes in the dependent variable affect or attribute to the independent variable. External validity: The extent that the relationship observed between the independent and dependent variable during the experiment is generalizable to the “real world.”

11. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Threats to Internal Validity in Experiments Threats to Internal Validity: o Selection Bias: subjects differences/ subjects not randomly assigned. o Testing Effects: influence of the pretest o History Effects: when some events occurs during the study and influence the DV o Maturation Effects: when changes occur within the subjects. o Mortality Effects: subject drop out. o Instrumentation change: differences between the pre-test and post-test.

12. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Threats to External Validity in Experiments Threats to External Validity: o Hawthorne effect: when study participants respond in a certain manner because they are aware that they are being observed. o Experimenter effect: when the researcher characteristic or behavior influence subjects behavior. o Reactive effect of the pretest: when the subjects have been sensitized to the treatment through taking the pretest.

13. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Symbolic presentations of research design Symbols: o O = The measurement or observation of a dependent variable o X = The manipulation, experiment or change, of an independent variable o R = Random assignment of subjects to experimental and control groups. ›Random assignment ensures that each subjects has an equal chance of being or placed into any of the groups.

14. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Types of experimental design True experimental. Quasi-experimental Pre-experimental

15. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy True experimental “true” experimental design is one that truly isolates the effects of the independent variable on the dependent variable while controlling for effects of any extraneous variables. Criteria o Manipulation o At least one experimental and one control group. o Random assignment

16. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy True experimental Types of true experimental: o Pretest-post test control group designs. o Post test only control group o Solomon four group design

17. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Pretest-post test control group designs Subjects are randomly assigned to groups, pretest is given to both groups, experimental group receive the interventions and control group receive the routine treatment then post test is given to both groups Experimental group R O 1 X O 2 Control group R O 1 O 2 Changes in the control group are due to all extraneous variables but not the independent variables

18. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Post test only control group o Subjects are randomly assigned to groups, experimental group receive the interventions and control group receive the routine treatment, then post test is given to both groups Experimental group R X O 1 Control group R O 1 Use after-only design when a precise measure of the effects of extraneous factors is not necessary. We are only concerned about the experimental effect.

19. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Solomon for group design Subjects are randomly assigned to one of four groups (2 experimental and 2 control). Two of the groups are pretested ( one experimental and one control) Two of the experimental groups receive the intervention. Post test is given to all four groups. Experimental group 1 R O 1 X O 2 Control group 1 R O 1 O 2 Experimental group 2 R X O 1 Control group 2 R O 1

20. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Quasi-experimental designs Quasi-experimental designs, unlike true experimental designs, do not properly control for the effects of extraneous variables on dependent variables. There is no comparison group or subjects are not randomly assigned to each group. Types o Non equivalent control group o Time-series design.

21. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Non equivalent control group Similar to the pretest-post test control group design except that there is no random assignment of subjects: Experimental group O 1 X O 2 Control group O 1 O 2 o Selection bias major threat

22. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Time-series design The researcher periodically observes or measures the subjects The experimental treatment is administered between two of the observation O 1 O 2 O 3 X O 4 O 5 O 6

23. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Pre experimental design Very weak form of experimental The researcher has little control over the research. Types : o One shout case study o One group pre test post test

24. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy One shout case study Change the independent variable and, after some period of time, measure the dependent variable X O 1 e.g. a group of patients with DM might attend a diabetic class and be tested on their knowledge of diabetes after the class.

25. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy One group pre test post test First measure the dependent variable, then change the independent variable, and finally, take a second measurement of the dependent variable O 1 X O 2 e.g. A group of patient with DM would be given a pre test of their knowledge concerning DM then attend a diabetic class and be post tested at the end of the class

26. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Non-experimental Design Descriptive in nature There is no manipulation or control of variables The researcher only describe the phenomenon of interest. Researcher must attempt to control for extraneous variables

27. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Non-experimental Design A research design in which a researcher observes a phenomenon without manipulating the independent variables(s) No manipulation Independent variables have already occurred, so no control over them Clear, concise problem statement that is based on a theoretical framework, or natural phenomenon.

28. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Types of non Experimental Designs Survey study Correlational studies Comparative studies Methodological studies

29. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Survey study This involves administration of an instrument to collect data regarding characteristics of a group. Self report data. Can be conducted by phone, mail, or personally. Usually focus on what was done and what people plan to do in the future. Advantages include ability to provide information on populations using relatively small samples.

30. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Correlational studies This research looks at the relationship between variables. It does not involve manipulation or intervention. In correlation study the independent variable is the variable comes first in chronological order and that influences the other variables. correlation coefficient may be positive or negative and ranges from -1 to 1. Examines if variables covary Quantifies the strength or relationship between the variables (not cause & effect).

31. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Comparative studies Examines the differences between intact groups on some dependent variable of interest. Differ from experimental studies in the researchers ability to manipulate the independent variable. Classified as retrospective or prospective. Retrospective: dependent variable has already been affected by independent variable, link present events to past events. Prospective : link present events to presumed future effect, less common, considered stronger design.

32. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Methodological studies Concerned with the development, testing and evaluation of research instrument and methods

33. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Setting for research studies Field Experiments: The independent variables are manipulated and the measurements of the dependent variable are made on test units in their natural setting. Simulation studies: considered to be laboratory studies

34. Copyright ©2008 by Pearson Education, Inc. Pearson Prentice Hall Upper Saddle River, NJ 07458 Foundations of Nursing Research, 5e By Rose Marie Nieswiadomy Critique Quantitative Research design Is the design clearly identified in the research report. Is the design appropriate to test the study hypothesis. Is the study used an experimental design, was the most appropriate type of experimental design used. If the study used an experimental design, what means were used to control for threats to internal validity and external validity. Does the research design allow the researcher to draw a cause- effect relationship. If the design was non-experimental, would an experimental design have been more appropriate. What means were used to control for extraneous variables.