Lesson 7

Lesson 7: Interpreting Statistical Data

 

Focus

 

Survey and poll results are frequently used to sway public opinion. For that reason, it is important that you are able to interpret survey results and decide for yourself whether you agree or disagree with the survey results or the survey methodology (i.e., how the survey was conducted).

 

Technology has allowed for surveys and polls to be set up in a very short period of time. The polls or surveys can start generating responses almost immediately.

 

 

Users of social networking sites such as Facebook can set up a survey to help them decide which movie they should see that night. Users of restaurant rating apps can look at the number of “likes” to help decide which sushi place sells the best lunch. Tweets to a celebrity fashion critic’s Twitter account can give insight into public opinion on a new fashion trend.

 

Even news agencies use surveys and polls on their websites, Facebook pages, and Twitter accounts to gauge their viewers’ responses to current news stories. Information that used to take a specialized group of people days or weeks to gather can now be accomplished in the span of a 30-minute newscast.

 

But how confident can you be in the results of these informal surveys or polls? For instance, what is the probability that if a student polls all her friends on Facebook about whether she should go and see the new horror movie, her friends are going to say “YES!”? (Is this because it is a good movie or because her friends have a similar taste in movies?) Have you ever seen the confidence level or margin of error listed for these types of informal polls or surveys?

 

In Lesson 6 you began to consider the importance of reliability of results. Recall the survey you did in that lesson in which you looked at how confident you felt you need to be in the skills of your doctor, dentist, or sandwich maker. Do you feel that you need to have the same level of confidence in your doctor and an employee in a fast-food restaurant? If you are using data to help you make a decision, it would be good to know that you can have confidence in that data.

 

In this lesson you will investigate factors that affect the level of confidence in statistical data. In a society where you are constantly presented with opinion polls, surveys, and the opportunity to “like” or “dislike” from most mobile devices, it is important that you consider levels of confidence if you are going to make a decision based on the data.

 

This lesson will help you answer the following critical questions:

• What factors affect the level of confidence in statistical data?
  
  
• When presented with statistics in the media, what should you consider before making decisions based on the data presented?

Assessment

• Module 4 Project

All assessment items you encounter need to be placed in your course folder.

 

Materials and Equipment

• calculator