andrew_gelman_stats andrew_gelman_stats-2012 andrew_gelman_stats-2012-1340 knowledge-graph by maker-knowledge-mining
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Introduction: 13. A survey of American adults is conducted that includes too many women and not enough men in the sample. In the resulting weighting, each female respondent is given a weight of 1 and each male respondent is given a weight of 1.5. The sample includes 600 women and 380 men, of whom 400 women and 100 men respond Yes to a particular question of interest. Give an estimate and standard error for the proportion of American adults who would answer Yes to this question if asked. Solution to question 12 From yesterday : 12. A researcher fits a regression model predicting some political behavior given predictors for demographics and several measures of economic ideology. The coefficients for the ideology measures are not statistically significant, and the researcher creates a new measure, adding up the ideology questions and creating a common score, and then fits a new regression including the new score and removing the individual ideology questions from the model. Which of the follo
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1 A survey of American adults is conducted that includes too many women and not enough men in the sample. [sent-2, score-0.708]
2 In the resulting weighting, each female respondent is given a weight of 1 and each male respondent is given a weight of 1. [sent-3, score-1.052]
3 The sample includes 600 women and 380 men, of whom 400 women and 100 men respond Yes to a particular question of interest. [sent-5, score-0.805]
4 Give an estimate and standard error for the proportion of American adults who would answer Yes to this question if asked. [sent-6, score-0.309]
5 Solution to question 12 From yesterday : 12. [sent-7, score-0.086]
6 A researcher fits a regression model predicting some political behavior given predictors for demographics and several measures of economic ideology. [sent-8, score-1.052]
7 ) (a) If the original ideology measures are close to 100% correlated with each other, there will be essentially no benefit from this approach. [sent-12, score-1.147]
8 (b) If the original ideology measures are not on a common scale, they should be rescaled before adding them up. [sent-13, score-1.394]
9 (c) If the original result was not statistically significant, the researcher should stop, so as to avoid data dredging and selection bias. [sent-14, score-0.539]
10 (d) Another reasonable option would be to perform a factor analysis on the ideology mea- sures and create a common score in that way. [sent-15, score-1.015]
11 a is wrong because if the measures are highly correlated, the regression coefficients in the original model will be very noisy. [sent-17, score-0.907]
12 c is wrong because the average of a bunch of measures can be a good predictor even if the individual measures are noisy. [sent-18, score-1.071]
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same-blog 1 0.99999994 1340 andrew gelman stats-2012-05-23-Question 13 of my final exam for Design and Analysis of Sample Surveys
Introduction: 13. A survey of American adults is conducted that includes too many women and not enough men in the sample. In the resulting weighting, each female respondent is given a weight of 1 and each male respondent is given a weight of 1.5. The sample includes 600 women and 380 men, of whom 400 women and 100 men respond Yes to a particular question of interest. Give an estimate and standard error for the proportion of American adults who would answer Yes to this question if asked. Solution to question 12 From yesterday : 12. A researcher fits a regression model predicting some political behavior given predictors for demographics and several measures of economic ideology. The coefficients for the ideology measures are not statistically significant, and the researcher creates a new measure, adding up the ideology questions and creating a common score, and then fits a new regression including the new score and removing the individual ideology questions from the model. Which of the follo
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Introduction: 12. A researcher fits a regression model predicting some political behavior given predictors for demographics and several measures of economic ideology. The coefficients for the ideology measures are not statistically significant, and the researcher creates a new measure, adding up the ideology questions and creating a common score, and then fits a new regression including the new score and removing the individual ideology questions from the model. Which of the following statements are basically true? (Indicate all that apply.) (a) If the original ideology measures are close to 100% correlated with each other, there will be essentially no benefit from this approach. (b) If the original ideology measures are not on a common scale, they should be rescaled before adding them up. (c) If the original result was not statistically significant, the researcher should stop, so as to avoid data dredging and selection bias. (d) Another reasonable option would be to perform a factor analysi
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Introduction: 14. A public health survey of elderly Americans includes many questions, including “How many hours per week did you exercise in your most active years as a young adult?” and also several questions about current mobility and health status. Response rates are high for the questions about recent activities and status, but there is a lot of nonresponse for the question on past activity. You are considering imputing the missing values on the question, “How many hours per week did you exercise in your most active years as a young adult?” Which of the following statements are basically correct? (Indicate all that apply.) (a) If done reasonably well, imputation is preferred to available-case and complete-case analysis. (b) If you do impute, you should also present the available-case and complete-case analysis and analyze how the imputed estimates differ. (c) It is OK to include current health status variables as predictors in a model imputing past activities: anything that adds informati
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Introduction: 13. A survey of American adults is conducted that includes too many women and not enough men in the sample. In the resulting weighting, each female respondent is given a weight of 1 and each male respondent is given a weight of 1.5. The sample includes 600 women and 380 men, of whom 400 women and 100 men respond Yes to a particular question of interest. Give an estimate and standard error for the proportion of American adults who would answer Yes to this question if asked. Solution to question 12 From yesterday : 12. A researcher fits a regression model predicting some political behavior given predictors for demographics and several measures of economic ideology. The coefficients for the ideology measures are not statistically significant, and the researcher creates a new measure, adding up the ideology questions and creating a common score, and then fits a new regression including the new score and removing the individual ideology questions from the model. Which of the follo
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Introduction: 14. A public health survey of elderly Americans includes many questions, including “How many hours per week did you exercise in your most active years as a young adult?” and also several questions about current mobility and health status. Response rates are high for the questions about recent activities and status, but there is a lot of nonresponse for the question on past activity. You are considering imputing the missing values on the question, “How many hours per week did you exercise in your most active years as a young adult?” Which of the following statements are basically correct? (Indicate all that apply.) (a) If done reasonably well, imputation is preferred to available-case and complete-case analysis. (b) If you do impute, you should also present the available-case and complete-case analysis and analyze how the imputed estimates differ. (c) It is OK to include current health status variables as predictors in a model imputing past activities: anything that adds informati
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Introduction: 15. A researcher conducts a random-digit-dial survey of individuals and married couples. The design is as follows: if only one person lives in a household, he or she is interviewed. If there are multiple adults in the household, one is selected at random: he or she is interviewed and, if he or she is married to one of the other adults in the household, the spouse is interviewed as well. Come up with a scheme for inverse-probability weights (ignoring nonresponse and assuming there is exactly one phone line per household). Solution to question 14 From yesterday : 14. A public health survey of elderly Americans includes many questions, including “How many hours per week did you exercise in your most active years as a young adult?” and also several questions about current mobility and health status. Response rates are high for the questions about recent activities and status, but there is a lot of nonresponse for the question on past activity. You are considering imputing the mis
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Introduction: 11. Here is the result of fitting a logistic regression to Republican vote in the 1972 NES. Income is on a 1–5 scale. Approximately how much more likely is a person in income category 4 to vote Republican, compared to a person income category 2? Give an approximate estimate, standard error, and 95% interval. Solution to question 10 From yesterday : 10. Out of a random sample of 100 Americans, zero report having ever held political office. From this information, give a 95% confidence interval for the proportion of Americans who have ever held political office. Solution: Use the Agresti-Coull interval based on (y+2)/(n+4). Estimate is p.hat=2/104=0.02, se is sqrt(p.hat*(1-p.hat)/104)=0.013, 95% interval is [0.02 +/- 2*0.013] = [0,0.05].
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