Chapter 8 Pwpt Flashcards
Purpose of research design?
Provides the plan or blueprint
Is the vehicle for systematically testing research questions and hypotheses
Provides structure for maintaining control
Maintaining control prevents?
The effects of extraneous, mediating or intervening variables on the dependent variable or outcome
Avoid bias or threats to internal validity
How are objectivity and accuracy addressed?
By a thorough literature review
Accuracy means that
All aspects of the study work systematically from the research question
Variables measured are valid, reliable and objective
Internal validity
The experimental treatment resulted in observed facts
Valid is?
Measuring what they say they measure
Reliable is?
Consistent measurements obtained
Objective is?
Address issues of bias
Bias is?
When other factors explain the results
Feasibility considerations?
Facility and equipment availability Expense Experience Ethics Time Subjects
Independent variable is?
Variable that will have an effect on the dependent variable Usually manipulated (to experimental group)
The dependent variable is?
Not manipulated
The variable the researcher is interested in explaining
The goal of quantitative research is to?
Support a cause and effect relationship between the independent and dependent variable
PICO format?
P-population
I-intervention (independent variable)
C-comparison
O-outcome (dependent variable)
What are threats to internal validity? What type of variables are these threats?
Variables that occur during the study that interfere with the independent/dependent variables
Extraneous, intervening, mediating variables
How could I limit the effects of extraneous variables?
Use a homogenous sample (similar participants)
Use consistent data collection procedures
What does homogeneity do?
Limits generalizability or the potential to apply the results of a study to other populations which is a threat to external validity
Internal validity threats!
History Maturation Testing Instrumentation Mortality Selection bias
External validity threats!
Selection effects
Reactive effects
Measurement effects
Controlling the experiment means?
Reducing extraneous variables
How do you control extraneous variables?
Use of a homogenous sample
Use of consistent data collection procedures
Training and supervision of data collectors and interventionists
Manipulation of the independent variable
Randomization
What is randomization?
Each subject has an equal chance of being assigned to the control group or experimental group
Randomization assumes that any important…
Intervening, extraneous, or mediating variables will be equally distributed between the groups to minimize bias
Internal validity threat: history
Social media influences/impacts experiment
Internal validity threat: maturation
Subjects grow older and wiser between pre-test and post-test
Internal validity threat: testing
Gained experience from previous test
Internal validity threat: instrumentation
Changes in equipment used to make measurements or observational techniques
Internal validity threat: mortality
The loss of study subjects. Subjects remaining in study must be similar to subjects that dropped
Internal validity threat: selection bias
Individuals deciding to participate or not, they may only get motivated individuals
What does external validity do?
Questions the conditions of the study design as a factor in the results
External validity threat: selection effects
Numbers of available subjects are low or not accessible
External validity threat: reactive effects
Productivity increased because they saw they were being studied
Hawthorne effect
External validity threat: measurement effects
A pre test may “prime” the subjects and effect results
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. A count at the end of the summer semester indicates an increased number of students who completed testicular self-examinations
Mortality
