answers, 100% verified. Graded A
What is the difference between a survey and an experiment? - ✔✔-Survey-provide a
quantitative/numeric description of trends, attitudes, or opinions of a population by studying a sample
of that population; generalize/draw inferences to the population
-Experiment-also study a sample and generalize to the population, but tests the impact of a treatment
(or intervention) on an outcome, controlling for all other factors that might influence that outcome
What guides the study design? - ✔✔the research question
when doing a survey design, what are the checklist criteria to look at? - ✔✔-check the purpose
-cross sectional vs longitudinal
-form of data collection
-random sample vs convenience sample
-stratification
-sample size
-instrumentation
what is the difference between cross sectional and longitudinal? - ✔✔cross sectional is data collected at
one point in time.
longitudinal is data collected over time.
what is the difference between a random sample and a convenience sample? - ✔✔random-each
individual in the population as equal probability of being selected.
convenience-respondents are chosen based on their convenience and availability.
,what does stratification mean? - ✔✔-Means that specific characteristics of an individual (ex. gender) are
represented in the sample and the sample reflects true proportions in the population of individuals with
certain characteristics
-Requires that characteristics of the population members be known so that the population can be
stratified first before selecting the sample
Sample size is usually based off what? - ✔✔selected a fraction of the population or margin of error they
are willing to tolerate.
Study is only as good as the ___ and ___. - ✔✔reliability and validity
the larger the sample size, the more you are able to gain meaningful information. T or F? - ✔✔true
What is a power analysis? - ✔✔method used to calculate how many participants are in a study; based
on prior studies on certain topic or run through by a calculator.
What is the difference between independent and dependent variables? - ✔✔o Independent variables-
what you do (program)
o Dependent variables-outcomes/outcome measures; what's being measured
what is the difference between internal and external validity? - ✔✔o Internal-the certainty to which we
can attribute the study outcome to the independent variable; less generalizable
o External-relates to the patient population, clinical setting, treatment and measurement variables that
the study can be generalized to
threats to internal validity include... - ✔✔history, maturation, testing, attrition, regression to the mean,
selection bias, instrumentation, sequence effects, and contamination.
How can history threaten internal validity? - ✔✔external even can influence study outcome.
, How can maturation affect internal validity? - ✔✔time influences studyoutcome; people change.
how can testing affect internal validity? - ✔✔repeated testing of participants influences study outcome,
i.e. the learned effect.
what is the learned effect? - ✔✔measuring dependent variables multiples times; could get better or
worse.
how does attrition affect internal validity - ✔✔loss of subjects during experiement influences study
outcomes.
how does regression to the mean affect internal validity? - ✔✔natural tendency for people to change
towards the average influences study outcome.
how does selection bias affect internal validity? - ✔✔bias in selecting individuals for different treatment
groups influence study outcomes
What is a selection-attrition interaction threat? - ✔✔when you know what the selection bias is you
name it with the concurrent interanl validity.
how can instrumentation affect internal validity? - ✔✔changes to tests and measurements can influence
a study outcome.
how can sequence effects affect internal validity? - ✔✔prior experiences in the study influence current
performance
how can contamination affect internal validity? - ✔✔when information passes to the participants in the
study
o Diffusion of Treatment-people in the study talk to each other, control group participants learn about
the experimental treatment
o Rivalry-participants boost performance to not look bad
o Resentment-people perform poorly because they resent being in control group