Unit 3 Ap Stats Review FLASHCARDS
Experimental units can be identified by who is being applied to the treatments and who is being measured from.
Matched pair design means two things that are similar.
Statistically Significant-observe a difference that is so large that you can rule out chance variation that it is not a coincidence
P-value- value of observing the difference less than 5%, then it is statistically significant
Bias- The result you are seeing is overestimating or underestimating the actual true value and being done systematically.
Volunteer Bias- people choose to respond normally to people who feel very strongly about it
Nonresponse Bias- People choose to not respond the survey so you don’t know about that group and how the people feel then the ones that did respond.
Undercoverage Bias- part of the population is excluded from the sample
Wording Bias- When the survey wording is leading to the response
4 Key Experimental Principles
Control, Replication (meant to rule out chance variation), Random assignment, Comparison
Simple Random Sample - every group of size n has the chance of being selected
Stratified Random Sample- more specific results, break them into strata(like gender or age ), similar purpose as a randomized block design
Cluster- All from some of the groups, spread out over a large area and look at everything in that group.
Systematic random sample- Randomly pick each person 1-20 start with the 4 one and then go to the 8 and continue on.
Population- the entire group of individuals that you hope to get results from
Sample- A representative subset of a population that is being examined in hope of learning about the population
Observational Study- Researchers do not assign treatments but they rather observe them or certain outcomes are measured.
Voluntary response sample- the researchers puts out a request for members of a population and they decide whether they want to be part of the sample
Convenience Sample - The researcher chooses a sample that is readily available in some nonrandom way like people walking on the street and getting polled.
Experimental Study- A treatment is intentionally introduced and result or outcome is observed.
Control- The group is an experiment that does not receive any treatment or manipulation.
Random Assignment- Placing participants into different treatment groups using randomization.
Factors- Variables in the study that we believe will influence the results
Levels- a measure or a scale to distinguish between measured variables that have different properties.
Treatments- The process, intervention that is applied to each subject in an experiment.
Completely randomized Design-Experimental units are randomly assigned to treatments equally by chance.
Randomized Block Design- Subjects or experimental units are grouped into blocks with different treatments and to be tested randomly in the units in each block.
Blinding- The participants can’t know which group they are sorted into
Single Blind- When the subjects in an experiment do not know if they are in the treatment or control group
Double Blind- When the subjects as well as the researcher do not know which subjects are in the treatments or control groups
Placebo- A fake treatment that is given to the control group to help prevent the placebo effect
Placebo effect- When a person appears to improve after taking a placebo.
Inference- Using data to make conclusions about a larger population.
Random Selection- Simple random sample is obtained by randomly selecting individuals from a target population.