Statistic Studies and Questions answered for discussion post. Due today. Do not respond if you cant fulfil the obligation Ty
Week 3
Quantitative Research Designs
Quantitative Methods
Houser states that "Quantitative research is defined as research that is based on measurement and the quantification of data. Whatever the dependent variable of interest in quantitative research, there must be a way to transform it into numbers a) dependent variable-The variable that is affected by the independent variable. b) independent variable-Generally, the variable that is manipulated and affects another variable, that is, the dependent variable. There are also measurement types of independent variables that are not manipulated but are hypothesized to affect another variable. c) extraneous variable-A variable in a study that has the potential to influence results but that is not the focus of the study.
Symbols for Depicting Experimental Designs
Researchers use the following symbols in their representations of research designs.
R = Random assignment of participants to groups X =exposure of the group to treatment or manipulation of a targeted condition O =observation or measurement of the dependent variable What is the difference between a control group and a comparison group?
Experimental Designs
Two criteria differentiate true experimental designs from others, and they are: 1. Random assignment to groups 2. Manipulation of the independent variable. The text describes three true experimental designs, what are they? Pretest-posttest equivalent group, a posttest-only group, and the Solomon Four-Group Design. Later in the course, we will discuss the strengths and weaknesses of these designs.
Pretest-Post-test True Experimental Design
Using the symbols previously discussed, denoted below is the pretest-post-test equivalent group design.
Group 1: R O1 X O2
Group 2: R O3 O4
There is random assignment of subjects to groups. Group 1 is the experimental group, and the X denotes an intervention or manipulation of a condition or experience of the subjects. The second group is the control group and receives no manipulation. Both groups receive a pretest and a posttest. For example: If I was going to provide brain training to a group of subjects to determine its’ effectiveness on memory. The X in Group 1 would be the brain training! Group 1 receives the training and group 2 does not.
Post-test Only Experimental Design
Using the symbols previously described, denoted is the post-test only experimental design.
Group 1: R X1 O1
Group 2: R X2 O2
Try to create a mock study using the post-test only design. Lastly, using the symbols previously described, denote the Solomon Four-Group design.
Group 1:R O1 X1 O2
Group 2:R O3 O4
Group 3:R X1 O5
Group 4:R O6
Quasi-Experimental Designs
Two factors define an Quasi-Experimental research design 1) No random assignment 2) Manipulation of the independent variable
Pre-Experimental Designs
The text describes three pre-experimental designs. Pre-experimental designs……. 1) do not include random assignment to groups 2) do not typically offer comparison groups or multiple baseline assessments 3) generally allow manipulation of the independent variable These designs include: one-shot case study, one-group pretest-post-test design and static group comparison. Using the symbols previously described, denote one design.
Practice # 1
Using ProQuest, locate and read the article in Psychological Medicine (2011), 41, 373-383. "A randomized trial of sertraline, self-administered cognitive behavioral therapy, and their combination for panic disorder" by D. Koszycki, M. Taljaard, Z. Segal and J. Bradwejn published Using the symbols previously discussed, denote the research design of this study. This study represents which type of design? Post your answer.
Practice # 2
Using ProQuest locate and read the article titled "Frequency of Provider Contact After FDA Advisory on Risk of Pediatric Suicidality with SSRIs."
Using the symbols previously discussed, denote the research design. What type of study does this research represent? Post your answer!
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Descriptive Research Designs
Two factors define descriptive designs 1) No random assignment 2) No manipulation of an independent variable The text outline four types of descriptive designs: survey, observational, correlational, and causal comparative. Describe each of these types in your notebook.