Question

hw 3 - bias in studies
identify the type of sampling method used and describe any bias it may create.

1. our principal asks the high school teachers to fill out a survey about proficiency - based grading so he can report to the school board how all teachers in the district feel about pbg.
2. in february, mr. w plans to send out a mass e - mail using all of the student e - mails for seniors in order to collect data about their first semester grades.
3. mrs. d wants the p.e. department to purchases a new model of heart monitors but needs data to support her claim that the new models are needed. she orders a sample of heart monitors that she assigns to all of the students who have been failing her class, and she uses the current/older models with students who have been passing.

determine the question/choice bias used. then rewrite the survey question to help eliminate this bias.

1. do you feel like the students and staff at our school are friendly?
2. did you hear about the terrorist attack via social media, a news broadcast, the radio, or from another student?
3. what is your typical mile pace? 6 - 8, 8 - 10, 10 - 12, 12 - 14, 14+
4. in view of escalating environmental degradation and predictions of serious resource depletion, would you favor economic incentives for recycling of resource - intensive consumer goods?
5. the majority of students say math is easy. what grade do you have in math class?

Explanation:

1. Sampling Method and Bias:

• Sampling Method: Convenience sampling (only high - school teachers in the principal's school are surveyed instead of all district teachers).
• Bias: Under - coverage bias. The sample does not represent all teachers in the district.

1. Sampling Method and Bias:

• Sampling Method: Census (using all senior student emails). There is no sampling bias in terms of selection (assuming all senior emails are valid), but there could be non - response bias if not all seniors respond.

1. Sampling Method and Bias:

• Sampling Method: Biased experimental design (assigning new heart monitors to failing students and old ones to passing students).
• Bias: Selection bias. The groups are not randomly assigned, which can confound the results (e.g., failing students may have other factors affecting their performance rather than just the heart monitor).

1. Question Bias and Rewrite:

• Bias: Leading question. The use of “feel like” and the positive connotation of “friendly” can influence responses.
• Rewrite: “Are the students and staff at our school friendly? (Yes/No)”

1. Question Bias and Rewrite:

• Bias: Limited response options. It assumes the only ways to hear about the attack are social media, news broadcast, radio, or another student.
• Rewrite: “How did you hear about the terrorist attack?”

1. Question Bias and Rewrite:

• Bias: Uneven class intervals. The intervals (e.g., 6 - 8, 8 - 10) are not of equal width in terms of the number of values (except for the last one which is open - ended).
• Rewrite: “What is your typical mile pace? (Please provide a numerical value)”

1. Question Bias and Rewrite:

• Bias: Leading question. The description of “escalating environmental degradation and predictions of serious resource depletion” can influence the response.
• Rewrite: “Would you favor economic incentives for recycling of resource - intensive consumer goods?”

1. Question Bias and Rewrite:

• Bias: Leading question. The statement “The majority of students say math is easy” can influence the response about the grade.
• Rewrite: “What grade do you have in math class?”

Answer:

1. Sampling Method: Convenience sampling; Bias: Under - coverage bias.
2. Sampling Method: Census; Potential Bias: Non - response bias.
3. Sampling Method: Biased experimental design; Bias: Selection bias.
4. Bias: Leading question; Rewrite: “Are the students and staff at our school friendly? (Yes/No)”
5. Bias: Limited response options; Rewrite: “How did you hear about the terrorist attack?”
6. Bias: Uneven class intervals; Rewrite: “What is your typical mile pace? (Please provide a numerical value)”
7. Bias: Leading question; Rewrite: “Would you favor economic incentives for recycling of resource - intensive consumer goods?”
8. Bias: Leading question; Rewrite: “What grade do you have in math class?”