Math Mod Unit 4 Lesson 4

What are the four questions that must be answered as we begin to communicate our findings to other people?

- Did we employ random sampling methods? - Why did we choose our method of data collection? - What was the focus for our data collection? - Were our survey questions unbiased?

We chose a survey because it was convenient and we could get a lot of responses quickly. We collected this data to find out the favorite NFL team of people who live in Texas. We took the bus to each of these cities and stood in the station and asked people as they got off the buses if they would fill out our survey. We asked people who looked friendly and who did not look to be in a hurry to get somewhere, as we did not want to inconvenience anyone. We don't see any place for bias to have entered into our survey. Was this truly a random sampling method? Why or why not?

No; There was a very limited selection of people who could have answered the survey. First, only people getting off of buses were asked. Second, only "friendly looking" people were asked. Third, only people who did not look to be in a hurry were asked. Every person did not have an equal chance of being asked.

We chose a survey because it was convenient and we could get a lot of responses quickly. We collected this data to find out 9th- and 10th-grade students' favorite snacks. We picked a day when there were no students absent and gave the survey to every 9th- and 10th-grade student so every student responded. The only possible source for bias that we see is that we lined up the words "fresh fruit" under the words "9th grade" and the word "pizza" under the words "10th grade." Was this truly a random sampling method? Why or why not?

Yes; every student had an equal chance to respond.

We chose a survey because it was convenient and we could get a lot of responses quickly. We collected this data to find out the favorite NFL team of people who live in Texas. We took the bus to each of these cities and stood in the station and asked people as they got off the buses if they would fill out our survey. We asked people who looked friendly and who did not look to be in a hurry to get somewhere, as we did not want to inconvenience anyone. We don't see any place for bias to have entered into our survey. The people who administered the survey believe this survey to be unbiased. Was the survey biased? If so, identify at least one possible source of bias.

Yes; perhaps people had more than one favorite team or no favorite team. That was not a choice for them to respond. The survey was administered only in three cities, not all of Texas. The survey was also given to people who got off of a bus in these cities in Texas. What if they did not live in Texas, but were just visiting?

We chose a survey because it was convenient and we could get a lot of responses quickly. We collected this data to find out 9th- and 10th-grade students' favorite snacks. We picked a day when there were no students absent and gave the survey to every 9th- and 10th-grade student so every student responded. The only possible source for bias that we see is that we lined up the words "fresh fruit" under the words "9th grade" and the word "pizza" under the words "10th grade." Are there any other possible sources of bias in the survey questions? If so, what are they?

Yes; students might have other favorite snacks besides fresh fruit and pizza, but these were the only choices given.