Exam 13: Uncertainty of Numeric Estimates

Find a research paper on the internet that uses traditional statistical hypothesis testing and reports on measures of uncertainty. Identify the inferential statistics and uncertainty measures used in the study. Comment on these statistics and measures.

What are the two factors that determine the standard error of a point estimate?

What is hypothesis testing?

Why is inferential statistics from a sample collected using nonprobability methods problematic?

The sample size drawn from a population was increased from 200 cases to 1,000 cases. This increase in sample size reduced the standard error of summary statistics calculated from the independent variable in the data.

What is meant by publication bias? Choose the best answer.

Which of the following is not affected by sample size?

Discuss any drawbacks you observe in the traditional statistical methods used by the authors of the paper in question 1. How would you revise the approach taken by the authors on significance testing, using more current approaches? Explain your answer.

What is the current critique of a statistically significant estimate found using traditional research methods?

Write a hypothesis statement on cigarette smoking and the probability of cancer as the variables of interest. You may have 2 statements for the null and the alternative hypothesis respectively.

In a research study the estimate of variable X is found to be 12.8, with a confidence interval of 10.8 and 14.8. A second estimate of variable X, using a different sample, was 14.2, with a confidence interval of 11.2 and 17.2. What can we say about the difference in the two estimates, if both had valid p values? Choose the best answer.

Which measure is used to analyze difference in means in an ANOVA test?

The standard error is an estimate of the sampling error of a point estimate.

Choosing a higher confidence level results in a smaller range for margin of error of a sampling estimate.

Three different samples were drawn from a population. The mean of variable AGE for the three samples was found to be 24, 27, and 21, respectively. What is the sampling variation in AGE?

The mean income of residents of Long Island City, NY, was $32,500. The mean income of a random sample of 200 residents of Long Island City was found to be $28,900. The difference between the two numbers ($3,600) is known as sampling error.

A confidence interval is calculated as Point Estimate (+/-) 2*Margin of Error.

Distinguish between random error and bias. Illustrate the differences with the help of an example.

The higher the precision of a sample estimate, the lower is its sampling error.

The sample mean of the variable height in a data set was found to be 68 inches, with a standard error of four inches. The researcher reported that the population or true mean height fell within one margin of error of the sample mean, at the 95% confidence level. What is the chance that the true mean is 75 inches or more?