Part I
Identify the type of bias (selection, response/measurement, or non-response) AND explain why this bias may be present. i.
A drywall inspector uses her new digital tape measure to determine the size of drywall sheets randomly selected from a recent shipment to her business. Afterwards, her assistant realizes that he forgot to calibrate the tape measure. ii.
To determine if an ice cream shop can be successful in a particular town, a market researcher randomly selects 150 households and mails them a questionnaire about their ice cream eating habits and flavor preferences. Only 4 questionnaires are returned. iii.
A researcher is conducting a survey about drug use among teenagers. She randomly selects twelve high schools and has teachers at the schools interview randomly selected students there. iv.
A college vice-president wants to conduct a study on the achievement of undergraduate students. He selects the first 50 students who enter the building on a given day and administers his survey.
Chapter 2
Activities Worksheets

Part II
Identify the sampling method (simple random, stratified, cluster, systematic, or convenience) i.
Glamour magazine collects data on its readers by asking them to fill out and send in a survey from the March issue of the magazine. ii.
A farmer divides his orchard into 50 subsections, randomly selects four, and samples all the trees within the four subsections to approximate the yield of his orchard. iii.
A group of lobbyists has a list of the 100 senators of the United States. To determine the
Senate’s position regarding farm subsidies, they decide to talk with every seventh senator on the list, starting with the third. iv.
A teacher puts all her students’ names in a hat, then selects three names from the hat. These students will take a standardized test. v.
The President of a college randomly selects two students from each department to serve on an advisory board.
Chapter 2
Activities Worksheets

Part I i. Measurement Bias – digital tape measure not calibrated ii. Non-Response Bias – only 4 out of 150 questionnaires returned iii. Response Bias – students may lie about drug use to their teachers iv. Selection Bias – only students who come to the building early in the morning are sampled
(leaves out late sleepers, people who work or study at home in the morning)
Part II i. Convenience ii. Cluster iii. Systematic iv. Simple Random v. Stratified
Chapter 2
Activities Worksheets

1. Form groups of 3 or 4 with your fellow students.
2. Here is your research question:
Do students learn better by working in groups?
3. Answer the following: a. What is your response variable? (What are you measuring and how will you measure it?) b. What is the factor of interest? What “treatments” will you use? c. Name one extraneous factor to consider. Will you control this factor? Will you use blocking? Explain your choice. d. How will you incorporate randomization in your design? e. How will you incorporate replication in your design?
Chapter 2
Activities Worksheets