Design lectures Flashcards
What are the three elements of an experimental study
random assignment
manipulation of the Tx (some get it, others dont)
control
What is the diff between quasi exp studies and exp studies
quasi will be missing one of the three but always has a manipulation of the Tx
Who are the accessible population
those that you drew your sample from
Who are the target population
those you will generalize your findings to
What are the main elements of design
study setting timing of data colleciton sample seleciton type of data collected issues of control
What are some things that skew internal validity
history maturation testing instrumentation mortality selection bias
What does history mean in terms of skewed internal validity
current events going on in the world outside of your study have an indirect influence on your study
What does maturation mean in terms of skewed internal validity
the changes you see might be a result of growth and dev rather than your intervention
What does testing mean in terms of skewed internal validity
the results were skewed based on how the act of testing influenced the results
What does instrumentation mean in terms of skewed internal validity
an error like changing some instrumentation during the study interferes with the internal validity
What does mortality mean in terms of skewed internal validity
the completers of the study are different from the non-completers
What does selection bias mean in terms of skewed internal validity
when people are allowed to self select into a study, they may be different from other people that wouldn’t self select
What are the things that can skew external validity
effects of selection
reactive effects
effects of testing
What does effects of selection mean in terms of skewed external validity
are the people in the study a true representation of the general pop
What does reactive effects (HAWTHORNE EFFECT) mean in terms of skewed external validity
the effect is relate to them being studied rather than actual interventions
What does effects of testing mean in terms of skewed external validity
the act of testing influences the outcome of the test
What are the 4 types of timing of data collcetion
retrospective
historical
present or cross sectional
future or prospective
What is a retrospective study
looking back in time for a past cause of a current problem
What is a cross sectional study
looking at data from the current time
Does a non-experimental study manage the independent variable
no
What is another term used for a retrospective study
ex post facto
What are other terms used for prospective studies
longitudinal
repeated measures
What are some examples of non-experimental designs
relationships correlation/difference retrospective prospective survey
What does a classic RCT exp design look like
exp and control group, both receive a pretest, one receives the tx the other a placebo, both get a post test
What is an exp tests that helps to ID any effects of testing
solomom four design
after only
What does the solomon four design look like
normal design of the classic RCT, but add two more control groups, both dont have any pretest, both have post test, and only one is given the tx
What does the after only test look like
two groups (exp and cont)
no pretests
one gets the tx
both post test
What are some things to ID in the sampling
Was it a probability or non-prob sample
What is required for probability sampling
every person has an equal chance of being selected, like choosing every 3rd person
What are some examples of probability sampling
systematic
stratified random
cluster
What is cluster samping
randomly selecting further and further into a random selection strategy, like randoly selecting states, then schools, then from there populations
What are some examples of non-probability sampling
convenience
quota
network or snowball
What is convenience sampling
selecting a non-random group, like a teacher selecting their students
