click below
click below
Normal Size Small Size show me how
Stats Vocab
Question | Answer |
---|---|
Population | The group of individuals that we hope to learn about |
Sample | A part of the population that we examine in hope to learn about the population |
Sample survey | Questions that are given to a sample in hope of learning something about the entire population. EX: Polls |
4 types of Bias | 1) Relying on Voluntary response 2)undercoverage of the population 3) nonresponse bias 4) response bias |
Randomization | The best defense against bias. Each individual is given a fair, random chance of being select |
Matching | Force a sample to resemble specific attribute |
Sample size | # of individual in a sample. |
Census | A sample that consist of the entire population |
Population parameter | EX: the mean income of all employed people in the country |
Statistic, sample statistic | values calculated for sampled data |
Representative | a sample is representative if the statistics computed from it accurately reflect the corresponding population parameters |
Simple random sample | each set of (n) elements in the population has an equal chance of being selected |
Sampling frame | Lists of individuals from the sample |
Stratified random sample | population is divided into several strata, and random samples are drawn from each stratum. |
Cluster sample | entire groups or clusters are chosen at random |
Systematic sample | selecting individuals systematically from a sampling frame |
Multistage sample | sampling schemes that combine several sampling methods |
Voluntary response bias | individuals can choose on their own whether to participate in the sample. Sample base on voluntary response is always invalid. |
Convenience sample | individuals who are conveniently available. Not representative because every individual is not equally convenient to sample |
Nonresponse bias | large fraction of those sampled fail to respond. Those who do response are likely not to represent the entire sample |
Response bias | The people tell lies because you asked a sensitive question. EX: Do you do drugs? |
Sampling variability | tendency of randomly drawn samples to differ, one from another. |
interviewer bias | the person you having conducting the interview makes the person hesitant to answer the questions |
Reporting Bias | the individual tends to round when answering |