1. Chapter Statistics and Probability
Ch. 11.1Designing a Study

2. What is statistics?
Definition- the practice or science of collecting and analyzing numerical data in large quantities, especially for the purpose of inferring proportions in a whole from those in a representative sample.
Statistics is a discipline which is concerned with:
designing experiments and other data collection.
summarizing information to aid understanding
drawing conclusions from data
estimating the present or predicting the future.

3. Designing a Study Type of Studies
Statistical Study- data collected and used to answer questions about a population characteristics or parameter.
Term
Definition
Example
Survey
a means of obtaining information from a population or a sample of the population
taking a poll to learn who people will vote for in an upcoming election
Experiment
an operation in which something is intentionally done to people, animals, or objects, and then the response is observed
studying the differences between two
groups of people, one of which receives a treatment and the other a placebo
Observational Study
an examination in which individuals are observed and no attempt is made to influence the results
observing a group of 100 people, 50 of whom have been taking a treatment; collecting, analyzing, and interpreting the data
Type of Studies

4. Determine whether each situation describes a survey, an experiment, or an observational study. Then identify the sample, and suggest a population from which it may have been selected.
The school administrators want to start an after-school tutoring program. They send a questionnaire to 100 students randomly selected from those who had a grade-point average less than 75.
You want to know how students and parents feel about school uniforms.

5. Determine whether each situation calls for a survey, an experiment, or an observational study. Explain your reasoning.
You want to find opinions on the best computer game to buy.
You want to see if students who have a 4.0 grade point average study more than those who do not.
A restaurant plans to ask 100 randomly selected customers to determine which menu item is most popular.
A nutrition research group wants to determine whether ninth-grade students who reported having eating breakfast every school morning had higher standardized test scores than who did not report having eaten breakfast every school morning.

6. Bias vs Unbiased Survey Questions
This year, students had access to state-of-the-art computer labs. What is your opinion of the impact of these labs on student learning?
This year, students had access to computer labs. What is your opinion of the impact of these labs on student learning?
When writing survey questions, avoid questions that:
• are confusing or wordy.
• cause a strong reaction.
• encourage a certain response.
• address more than one issue.

7. Determine whether each survey question is biased or unbiased
Determine whether each survey question is biased or unbiased. If biased, explain your reasoning.
Don’t you agree that teachers should be paid more?
Which would you rather use to learn in classroom, a cell phone or a laptop
Do you pay for your own car insurance?
Do you ever watch movies online?
What is your current age?
Do you agree or disagree with the following statement? Teachers should not be required to not supervise students during lunch.

8. Design a Study
A group of students wants to conduct an experiment to test the claim that yawns in a high school classroom are contagious. State the objective of the experiment, suggest a population, determine the experimental and control groups, and describe a sample procedure.

9. Problem Set
Pg. 727 #10-24