Sampling Methods
What is the main difference between a simple random sample and a stratifies random sample?
Simple Random: selects individuals entirely by chance
Stratifies Random: divides the population into groups (strata) and samples from each
What is the difference between an observational study and an experiment?
Experiment: the researcher assigns treatments
Observational: they do not interfere
What is sampling bias, and how can it affect the results of a study?
Sampling bias occurs when some individuals are more likely to be selected than others, leading to unrepresentative results
How young is Mr. R?
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What is a census and why might it be impartial to conduct?
A census collects data from every individual in a population, but it can costly and time-consuming
Why might a researcher choose to use cluster sampling instead of simple random sampling?
Cluster sampling is more practical when the population is larger and spread out geographically
What is a control group and why is it important in experiments?
A control group does not receive the treatment and serves as a baseline for comparison.
What is the difference between non-response bias and voluntary response bias?
Non-responsive bias occurs when selected individuals do not participate, while voluntary response bias occurs when individuals choose to participate
What is Mr. R's favorite color?
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What is the difference between cross-sectional and longitudinal studies?
Cross-sectional: collects data at one point in time
Longitudinal : follow individuals over time
What is a disadvantage of using convenience sampling?
It leads to biased results since its not representative of the population
What is the purpose of randomization in an experiment?
It helps eliminate bias and ensures that treatment groups are comparable
What is a confounding variable, and how does it impact an experiment?
A confounding variable is related to both the explanatory and response variables, making it difficult to determine causation
HOW MANY MORE DAYS TILL GRADUATION!!
NOT MANY LEFT!
What is a matched-pairs design, and why is it used?
Matched-pairs design pairs individuals based on similar characteristics to reduce variability
How does systemic sampling work, and what is one potential issue with it?
It selects every nth individual from a list but it can lead to bias if there is a periodic pattern in the population.
What is a double-blind experiment, and why is it used?
Neither the subjects not the researchers know who is receiving the treatment, reducing bias
What is the difference between Type 1 and Type 2 errors in hypothesis testing?
Type 1: rejecting a true null hypothesis
Type 2: failing to reject a false null hypothesis
What is Mr. R's NATIONALITY
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What is a block experimental design and how does it reduce variability?