Which of the following is a concern when selecting subjects for an experiment? …
Ask subjects whether they prefer to be in the experimental group or the control group, then assign subjects based on their preference
.
What two features must a true experiment contain?
In general, designs that are true experiments contain three key features:
independent and dependent variables, pretesting and posttesting, and experimental and control groups
.
Which of these experimental designs control for all major threats to internal validity?
Post-Test Only Control Group Design
For large enough groups, this design can control for most of the same threats to internal and external validity as the classic controlled experimental design.
Which of the following is a threat to external validity?
What are threats to external validity? There are seven threats to external validity:
selection bias, history, experimenter effect, Hawthorne effect, testing effect, aptitude-treatment and situation effect
.
What does between-subjects mean in a between-subjects experiment quizlet?
between-subjects
design
.
different groups of subjects are randomly assigned to the levels of your independent variable
.
What are the 5 components of experimental design?
The five components of the scientific method are:
observations, questions, hypothesis, methods and results
.
What are the elements of a true experiment?
True experiments have four elements:
manipulation, control , random assignment, and random selection
. The most important of these elements are manipulation and control. Manipulation means that something is purposefully changed by the researcher in the environment.
What is the biggest threat to internal validity?
History, maturation, selection, mortality and interaction of selection and the experimental variable
are all threats to the internal validity of this design.
What are examples of threats to internal validity?
What are threats to internal validity? There are eight threats to internal validity:
history, maturation, instrumentation, testing, selection bias, regression to the mean, social interaction and attrition
.
How can we prevent threats to internal validity?
- Keep an eye out for this if there are multiple observation/test points in your study.
- Go for consistency. Instrumentation threats can be reduced or eliminated by making every effort to maintain consistency at each observation point.
What is an example of external validity?
External validity is another name for the generalizability of results, asking “whether a causal relationship holds over variation in persons, settings, treatments and outcomes.”
1
A classic example of an external validity concern is
whether traditional economics or psychology lab experiments carried out on college
…
What factors affect external validity?
- Population characteristics (subjects)
- Interaction of subject selection and research.
- Descriptive explicitness of the independent variable.
- The effect of the research environment.
- Researcher or experimenter effects.
- Data collection methodology.
- The effect of time.
What are the limits to generalizability in terms of external validity?
“A threat to external validity is an explanation of how you might be wrong in making a generalization from the findings of a particular study.” In most cases, generalizability is
limited when the effect of one factor (i.e. the independent variable) depends on other factors
.
Why is random assignment used in between subjects experimental research quizlet?
Randomly select the participants from the population. In a between-subjects experiment, participants are assigned to treatments using random assignment. Why is random assignment used?
It is an attempt to control participant variables so they don’t become confounding variables
.
What are within-subjects?
A within-subject design is
a type of experimental design in which all participants are exposed to every treatment or condition
. The term “treatment” is used to describe the different levels of the independent variable, the variable that’s controlled by the experimenter.
What is a major advantage of a within-subjects design?
The single most important advantage of a within-subjects design is that
you do not have to worry about individual differences confounding your results
because all treatment groups include the exact same partcipants.
