1. Explain the difference between a completely randomized experimental design and a randomized block design. Give an example of each. Why is a block design a better choice sometimes?

Things you MUST include:

• Definitions for each type of experimental design.
• An example of each type.
• A rationale for why randomized block design would be chosen over completely randomized.

2.

1. A researcher numbers each household in the city and uses a random number generator to select individual households for the sample. By chance, none of the households chosen were households of single millennials.

This is an example of (voluntary response bias/ sponsorship bias/ sampling error)

1. A company's receipts gives a website where customers can fill out a survey to receive a coupon.

This is an example of (undercoverage bias/ sponsorship bias/ voluntary response bias)

1. Your friend forgot she was supposed to conduct a poll of your high schools' students. She asks everyone in your homeroom if they think the school should have a new mascot. She presents the results to the student council.

This is an example of (sampling error/ sponsorship bias/ undercoverage bias)

3. A botanist is studying a newly identified mushroom disease. The botanist collected soil samples from randomly selected fields in each state to see if there were significant differences the mineral levels in fields with and without the disease.

1. What is the sample? (selected US botanists/ selected US diseases/ selected US mushroom fields)
2. How was the sample selected? (Census/ Convenience sampling/ Stratified sampling)

4. Choose the best method for choosing a sample and the best method to collect data. Remember to think about the definitions and the pros and cons of each before choosing your answers.

1. A dog food claims to make dogs coats shiner and healthier looking. A researcher wants to test the claims. They plan to randomly select pet store shoppers to participate and assign them to two groups.

Census or Sampling method: (Cluster sampling/ Convenience sampling/ Simple random sampling/ Stratified sampling)

Collection method: (Experiment/ Simulation/ Survey)

2. The Department of Homeland Security wants to test a computer virus that it has developed to combat hackers. They plan to test run the virus on randomly selected computers with pre-set "hacker" programs.

Census or Sampling method: (Census/ Cluster sampling/ Convenience sampling/ Simple random sampling/ Stratified sampling)

Collection method: (Experiment/ Simulation/ Survey)