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Definition
| We observe individuals and measure variables of interest but do not attempt to influence the responses. |
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Definition
| We deliberately impose some treatment on individuals in order to observe their responses. |
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Definition
| The entire group of individuals that we want information about. |
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Definition
| The part of the population that we actually examine in order to gather information. |
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Definition
| Studying a part in order to gain information about the whole. |
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Definition
| Attempts to contact every individual in the entire population. |
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Term
| Voluntary Response Sample |
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Definition
| Consists of people who choose themselves by responding to a general appeal; tend to be biased because people with strong opinions, especially negative opinions, are most likely to respond. |
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Definition
| Choosing individuals who are easiest to reach. |
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Definition
| A sampling method that systematically favors certain outcomes. |
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Term
| Simple Random Sample (SRS) |
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Definition
| Size n consists of n individuals from the population chosen in such a way that every set of n individuals has an equal chance to be the sample actually selected. |
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Term
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Definition
| A long string of the digits 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 with each entry in the table equally likely to be any of the 10 digits and the entries are independent of each other. |
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Term
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Definition
| The general framework for a method that uses chance to choose a sample. |
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Term
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Definition
| A sample chosen by chance; we must know what samples are possible and what chance, or probability, each possible sample has. |
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Definition
| The population is divided into groups of individuals, called strata, that are similar in some way that is important to the response. |
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Term
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Definition
| Divides the population into groups, or clusters. Some of these clusters are randomly selected. Then all individuals in the chosen cluster are selected to be in the sample. |
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Term
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Definition
| Occurs when some groups in the population are left out of the process of choosing the sample. |
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Term
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Definition
| Occurs when an individual chosen for the sample can't be contact or does not cooperate. |
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Term
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Definition
| The behavior of the respondent or of the interviewer that can bias an answer. |
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