Moderators are necessary for external validity to be established
. Moderators suggest that an association between two variables will extend to another variable. Moderators suggest that associations may not generalize to all subgroups of people.
How do you test for external validity?
The ultimate test of an experiment’s external validity is
replication — conducting the study over again
, generally with different subject populations or in different settings. Researchers will often use different methods, to see if they still get the same results.
Why does an examination of moderating variables inform external validity?
-moderators can inform external validity–it allows
us to see how the association may not generalize from one situation to the next
. when the relationship between two variables changes on the level of this other variable.
How can you make sure the external validity in research is achieved?
A study is considered to be externally valid
if the researcher’s conclusions can in fact be accurately generalized to the population at large
. (4) The sample group must be representative of the target population to ensure external validity.
What is external validity in experimental research?
External validity refers
to how well the outcome of a study can be expected to apply to other settings
. In other words, this type of validity refers to how generalizable the findings are.
Can moderators inform external validity?
What do you ask to assess external validity? -moderators can inform external validity–it
allows us to see how the association may not generalize from one situation to the next
. moderator (variable) when the relationship between two variables changes on the level of this other variable.
How do you calculate mediating variables?
If the change in the level of the independent variable significantly accounts for variation in the other variable
, then the variable is considered a mediator variable.
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 is the difference between external validity and generalizability?
External validity is a function of the researcher and the design of the research. Generalizability is
a function of both the researcher and the user
.
What are the two types of external validity?
The two types of external validity are
population validity
(whether you can generalize to other groups of people) and ecological validity (whether you can generalize to other situations and settings).
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.
Which kind of sample is best for external validity?
— In terms of external validity, the best sample is
a representative sample
— one in which every member of the population has an equal chance of being selected.
How do you ensure validity in quantitative research?
Validity is harder to assess than reliability, but it is even more important. To obtain useful results, the methods you use to collect your data must be valid:
the research must be measuring what it claims to measure
. This ensures that your discussion of the data and the conclusions you draw are also valid.
What affects internal and external validity?
Internal validity is
the degree of confidence
that the causal relationship you are testing is not influenced by other factors or variables. External validity is the extent to which your results can be generalized to other contexts. The validity of your experiment depends on your experimental design.
What improves external validity?
How can we improve external validity? One way, based on the sampling model, suggests that
you do a good job of drawing a sample from a population
. … That is, your external validity (ability to generalize) will be stronger the more you replicate your study.
Does sample size affect external validity?
The use of sample size calculation
directly influences research findings
. Very small samples undermine the internal and external validity of a study. Very large samples tend to transform small differences into statistically significant differences – even when they are clinically insignificant.
