2022 Introduction to Statistics in Research Mitchell 2nd ed

I N T R O T O R E S E A R C H : D A T A V I S U A L I Z A T I O N & C O M M O N S T A T T E S T S

To minimize non-response bias, a serious effort needs to be made to follow up with individuals who did not respond to the initial request.

Self-assessment: Types of Samples

You are considering a study of how colleges and universities in the USA handled COVID-19 by looking at their policies. You first divided all colleges/universities into six subgroups of similar types (small public, small private, medium public, medium private, large public and large private. Then you randomly selected three colleges from each group. Which sampling method did you

use?

Answer: stratified random sample

To find the average value of a home in Indiana, one averages the price of homes that are listed for sale with a realtor. What type of bias could result from this process?

Answer: selection bias

Does the design represent the population? Let’s look at a few sample scenarios and designs to understand a little about research design.

Does the design represent the population?

Caloric Content and Menu Item Selection:

The article “What People Buy from Fast - Food Restaurants: Caloric Content and Menu Item Selection” (Obesity [2009]: 1369-1374) reported that the average number of calories consumed at lunch in New Your City fast-food restaurants was 827.

The researchers selected 267 fast-food locations at random. The paper states that at each of these locations “adult” customers were approached as they entered the restaurant and asked to provide their food receipt when exiting and to complete a brief survey.

Will this study result in data that is representative of the population? Here are the four questions to ask!

Answer: The people who eat at fast-food restaurants in NYC.

Q1 What is the population of interest?

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