What is a statistical question? Asking Good Questions What is a statistical question?

Standard MCC6.SP.1. Recognize a statistical question as one that anticipates variability in the data related to the question and accounts for it in the answers. For example, “How old am I?” is not a statistical question, but “How old are the students in my school?” is a statistical question because one anticipates variability in students’ ages.

Essential Question What are the characteristics of a good statistical question, and how do I write a good statistical question?

is a statistical question. I wonder if, “Do you like sports?” is a statistical question. I wonder if, “Do you like sports?” is a statistical question? What makes a question a statistical question?

A common mistake that students make is asking questions that have too few or too many answers. Look at these questions and imagine what how the graphs might look.

Let’s begin with the question, “Do you like math Let’s begin with the question, “Do you like math?” When 6th graders at McKinley Middle School were asked this question, here were their responses. This is not a statistical question because there are only 2 possible answer choices – yes or no.

What do you like best about school?

Too Many Choices Now let’s look at the other question, “What do you like best about school?” Let’s imagine how this graph might look. Whoa! There are so many answers that everyone gave a different answer, except for computers which received 2 votes. This is not a statistical question because there are too many answer choices. The number of answers given is called, “variability”. Statistical questions should ideally have about variability of 4-6 answers. Also, this graph does not include the population that was sampled, or surveyed. Do you think the responses would be different if adults were asked this question instead of students?

What is Your Favorite Subject in School?

Let’s look at another question. “What is your favorite sport on TV Let’s look at another question. “What is your favorite sport on TV?” Is this a statistical question? How much variability would you expect, in other words, how many answer choices would you expect? Here is how the graph looks. Was it what you expected? It includes an interesting question, the population that was surveyed, and variability in the responses.

Think About…. Suppose you asked this question to the University of Georgia football team. Would it be a statistical question? There is no variability in the responses, so it is NOT a good statistical question.

Imagine how this data might be different if the people surveyed were the members of the University of GEORGIA football team. How would you expect the graph to look? Not surprising, but all of the responses were for football. This had an interesting question and the population surveyed is stated, but there is no variability in the responses. This is not a statistical question.

Asks about a topic of interest. Includes a specific population. Has variability in the responses.

Try this problem on your own. Which of these is a statistical question Try this problem on your own. Which of these is a statistical question? Is chocolate your favorite ice cream flavor? or What is your favorite flavor of ice cream? Which question will give you a variety of answers? The first question asks a question in which the only answers are yes or no. The second question will bring many more responses, so it is a statistical question.

How many miles do I live from school? How many miles do the students in my school live from school?

How many books did the students at Jeff Davis Middle School read this summer? How many books did you read today?

How can you create a statistical question that has variability?

Variability

How many answers could you expect to hear if you asked 16 sixth graders at Taylor Middle School this question, “What did you eat for dinner last night?”

Yikes! There are way too many different answers here and they all have 1 vote except for cheeseburgers which has 2. This question had too much variability because there are too many different answers.

Let’s Make It Better!!! What is the 6th graders’ favorite meal in the school cafeteria? What is the favorite Mexican food at Jeff Davis Middle School?

Think about the different answers you expect to hear and edit your question. Remember to state the population.

Let’s Practice Try this problem now. Rewrite this question to make a statistical question. Remember to think of the answers first before writing the question. “Do you like dogs?” This question is about dogs, so maybe we should find all of the types of dogs that students like. The new question could be, “What is the favorite breed of dog among students at Taylor Middle School?” You could also rewrite the question to say, “What types of pets do the students at Taylor Middle School own?” That information will tell you if the students like dogs.

Your Turn….

Try It! Write your own good statistical question.