Statistically speaking Students will be able to recognize a statistical question as one that anticipates variability in the data related to the question and accounts for it in the answers.

How many hours do children spend on video games per week? In 2012, a nationally representative study found that the average American 8- to-18 years old play video games for 13.2 hours per week. When information is gathered about a group, such as Americans from 8 to 18, the entire group is called the population. Because requesting information from each member of a large group can be difficult or impossible, researchers often study a part of the population, called a sample. For a random sample, members of the population are chosen at random. This gives every member of the population an equal chance of being chosen. A convenience sample is based on members of the population that are readily available, such as 30 people in the Plainfield school district. A biased sample does not fairly represent the population. For example, if a teacher asked the 6th grade students how many hours of video games were played during the week. This could be a biased sample because the population is not representative of all that play video games.

Analyzing Sample methods Indian Trail Middle school cafeteria: Student satisfaction Which sampling method will better represent the whole population and how do you know?

Analyzing Sampling Methods Predict the winner of the mayoral election: Which sampling method best represents the whole population

Analyzing sample methods HUSUPU Determine which sampling method will better represent the population. Justify your answer.

Analyzing Sample Methods HUSUPU Determine which sampling method better represents the population. Justify your answer.

Identifying Potentially Biased Samples What is the potential bias? How do you know?

Identifying the potential bias What is the potential bias? How could you change it to make it unbiased?

Find the bias or is it random?

Recognizing a good statistical question A good statistical question is: Random – sample group is chosen by chance Unbiased – question is representative of the population Anticipates variability – allows for choice in response

Recognizing a good statistical question **How old am I? Change it to make a good statistical question **Do you have a dog? Change it to make it a good statistical question? **Do you like pizza? Change it to make a good statistical question?

Is it a good statistical question? If not, change it. What is your favorite color? Only ask 6th grade students how old they are? Do you like heavy metal music? How many hours of sleep do you get per night?

In closing Think about three survey questions you would like to ask your classmates. Questions need to be both numerical and categorical in their responses? Write your questions down on paper.