Producing Data Flashcards
What are the two stages of production of data?
- sampling
2. study design
What is the goal of sampling?
get a sample that represents the population of interest well so that when we get to the inference stage, making conclusions based on this sample about entire population will make sense
What are the different types of sampling
- volunteer sample
- convenience sample
- systematic sampling
- simple random sample
What is a volunteer sample
individuals have selected themselves to be included
-almost guaranteed to be biased
What is a convenience sample?
individuals happen to be at the right time and place to suit the schedule of the researcher
-can be baised depeneding on situation
What is a sampling frame?
the list of potential individuals to be sampled
What is systematic sampling?
when individuals are sampled at random, except restrictions such as not allowing siblings or people of same last name
What is simple random sample
when individuals are sampled completed at random, without replacement, and each group of given size is just as likely to be selected as all other groups of that size
Which type of sampling is least likely to have any bas
simple random sampling
What are the three types of study design?
- observational study
- controlled experiment
- sample survey
Why can a casual relationship be difficult to establish with an observational study?
due to lack of control over outside variables (lurking variables)
- individuals may change their behavior because they know they are being observed
- indiviuals’ memory may be faulty if trying to recall something from the past
How do experiments allow researchers to take control of lurking variables in experiments?
randomized assignment to treatments, which provides more convincing evidence to causation
