ch11_12_13 - STA 2023 - Holbrook Understanding Randomness...

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Unformatted text preview: STA 2023 - Holbrook Understanding Randomness Chapter 11 Sample Surveys Chapter 12 Experiments and Observational Studies Chapter 13 11_12_13 - 1 STA 2023 - Holbrook Understanding Randomness Chapter 11 (Pages 289­291) 11_12_13 - 2 Randomness STA 2023 - Holbrook 1. Using a random number table or a random Using number generator, we can truly select a random sample. random 2. Random Sample A sample is a random sample if each element sample (i.e. person) in the population has an equally likely chance of being selected. (Also called a simple random sample (SRS). See Chapter 12.) simple 3. Try taking a random sample in class. 11_12_13 - 3 STA 2023 - Holbrook Sample Surveys Chapter 12 11_12_13 - 4 Key Terms STA 2023 - Holbrook 1. Sample Survey A questionnaire given to a small group of people in questionnaire the hope of learning something about the population. the 2. Representative Sample A sample is said to be representative if it exhibits sample characteristics of the population. characteristics 3. Biased Sample A sample is biased if it does not represent the sample population in some important way. population 4. Sampling Frame A list of individuals from which the sample is drawn. 11_12_13 - 5 Sampling Techniques STA 2023 - Holbrook 1. Simple Random Sample (SRS) A sample is a SRS if each element (i.e. person) in sample the population has an equally likely chance of being selected. selected. 2. Stratified Random Sample Divide the elements (i.e. people) into homogeneous Divide groups (strata) and take a SRS. groups 3. Cluster Sample Group the population into small clusters, take a SRS Group of clusters, and observe everything in the clusters. of 11_12_13 - 6 Sampling Techniques (continued) STA 2023 - Holbrook 4. Systematic Sample Randomly select an element (i.e. a person) and then Randomly select every kth element thereafter. select 5. Multistage Sample Using a combination of these above methods 11_12_13 - 7 STA 2023 - Holbrook Experiments and Observational Studies Chapter 13 (Pages 329­332) 11_12_13 - 8 Key Terms STA 2023 - Holbrook 1. Observational Study A study in which subjects are observed. 2. Experiment A study that assigns subjects randomly to study treatments. treatments. 11_12_13 - 9 ...
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This note was uploaded on 12/07/2011 for the course STA 2023 taught by Professor Staff during the Fall '11 term at Santa Fe College.

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