Statistics Math 125 - Module 1 Homework 1.5

What is a closed​ question? What is an open​ question? Discuss the advantages and disadvantages of each type of question.

-A closed question has fixed choices for​ answers, whereas an open question is a​ free-response question. -Closed questions are easier to​ analyze, but limit the responses. Open questions allow respondents to state exactly how they​ feel, but are harder to analyze due to the variety of answers and possible misinterpretation of answers.

What are some solutions to​ nonresponse?

-offer rewards and incentives -attempt callbacks

Suppose you are reading an article online when the following text appeared in a popup window: ''Would you be interested in participating in a short health dash related survey question mark If you qualify and complete this survey comma you will receive $ 5.00 . Your participation will make a difference.'' What tactic is being used to increase the response rate for this​ survey?

The company is using a reward in the form of the $5.00 payment and an incentive by telling the readers that his or her input will make a differences.

The manager of a shopping mall wishes to expand the number of shops available in the food court. He has a market researcher survey the first 100 customers who come into the food court during weekday evenings to determine what types of food the shoppers would like to see added to the food court. Complete parts​ (a) and​ (b) below.

(a) The survey has bias. Determine whether the flaw is due to the sampling method or the survey itself. For biased​ surveys, identify the cause of the error. What is the cause of the​ bias? Sampling bias (b) Suggest a remedy to the problem. Which of the following is the best way to remedy this​ problem? Ask customers throughout the day on both weekdays and weekends.

A creamery is considering opening a new store in another town. Before opening the store, the company would like to know the percentage of households in this town that regulary visit an ice cream shop. The market researcher obtains a list of households and randomly selects 150 of them. He mails a questionnaire to the 150 households that asks about ice cream eating habits. Of the 150 questionnaires mailed, 4 are returned.

(a) What is the type of​ bias? Non-response bias ​(b) What is a possible​ remedy? Conduct face-to-face or telephone interviews.

What does it mean when a part of the population is​ under-represented?

A part of the population is​ under-represented when it is proportionally smaller in a sample than in its population.

Surveys tend to suffer from low response rates. Based on past​ experience, a researcher determines that the typical response rate for an​ e-mail survey is 20​%. She wishes to obtain a sample of 250 ​respondents, so she​ e-mails the survey to 2500 randomly selected​ e-mail addresses. Assuming the response rate for her survey is 20​%, will the respondents form an unbiased​ sample? Explain.

Is the sample​ unbiased? No. The survey still suffers from undercoverage​ (sampling bias), nonresponse​ bias, and potentially response bias.

Why is it rare for frames to be completely​ accurate?

It is rare for frames to be accurate because frames are obtained​ periodically, whereas populations are constantly changing.

A poll is being conducted at a video game store nothing to obtain a sample of the population of an entire country. What is the frame for this type of​ sampling? Who would be excluded from the survey and how might this affect the results of the​ survey?

The frame is the entire population of the country. Any person who does not play video games is excluded. This could result in sampling bias due to under coverage.

What are the advantages of having a presurvey with open questions to assist in constructing a questionnaire that has closed​ questions?

The researcher can learn common answers.

Suppose a surveyor wants to conduct a phone survey about a new movie. He plans to take a simple random sample.​ However, some people are not at home. Do you believe this can affect the ability of the surveyor to obtain accurate polling​ results? If​ so, how?

Yes, especially if the people who are not at home have a trait that is not accurately represented by the remaining people in the sample.

Consider the two questions shown below. (a) Out of apples, oranges, bananas, and pears, which fruit is your favorite? (b) How much fruit do you eat in a week? Will the order in which the questions are asked affect the survey results? If so. what can the pollster do to alleviate this response bias?

Yes, question order will affect the survey results. The pollster should alternate the order of the questions given in the questionnaire so that different respondents receive questionnaires with the same questions but different question orderings.

The survey has bias.​ (a) Determine the type of bias.​ (b) Suggest a remedy. A polling organization conducts a study to estimate the percentage of households that have both parents sharing equally in household chores. It mails a questionnaire to 1139 randomly selected households across the country and asks the head of each household if he or she has both parents sharing equally in household chores. Of the 1139 households​ selected, 33 responded.

​(a) Which of these best describes the bias in the​ survey? Nonresponse bias ​(b) How can the bias be​ remedied? The polling organization should try contacting households that do not respond by phone or​ face-to-face.