Conducting Surveys

Imagine this scenario… You want to find out whether or not students would participate if you started a Glee Club at CCMS.

Interview every tenth teenager you see at the park this weekend. Which would be the best way to find out if students are interested? Interview every tenth teenager you see at the park this weekend. Interview CCMS students who are in the Choir Elective class. Interview every tenth student leaving the CCMS cafeteria at lunch. Which choice is best? Why is this best?

Some surveys are biased. A biased survey does not accurately represent an entire population. The sample size may be too small or only a specific group of people are surveyed.

Some surveys are biased. For example, if you only survey … Dodger fans 6th grade girls Your math teacher Why would these be biased?

Fifty middle school boys were asked the following question: “On a Friday night, would you rather play video games or watch Sports Center?” Is this a biased survey? How do you know?

In what ways is this survey biased? Every Saturday morning from 9:00 a.m. to 11:00 a.m., every 5th family entering Disneyland is asked “How much time, on average, do you spend with your children each week?”

Some surveys are random. A random survey is used to avoid bias. This type of survey aims to accurately represent an entire population by choosing participants at random.

In what ways is this survey random? Every 10th person entering the mall is asked “Who is your favorite author?”

You want to find out which restaurant is the most popular in Culver City. Talk with your partner about ways to select a random sample. Be ready to share your ideas with the class.

Two common ways to survey… Convenience sampling Selecting people for the survey who are easiest to ask Voluntary sampling When the people involved in the survey choose to be involved (like surveying the people in this room) (such as, write-in or call-in surveys.. like Dancing with the Stars!) Convenience and voluntary sampling are often biased. Why do you think this is so?

How to Conduct a Survey Develop a survey question Collect and organize data Display and analyze the data Summarize the results

Develop a Survey Question Statistical versus Non-statistical questions Numerical versus Categorical questions

Collect and Organize Data Select participants for your survey or gather data from another source (e.g.; book, online, etc.) Decide your sample size Consider whether your survey sample will be biased or random Determine where, when, and how you will collect your data Think about the ways you will record and organize your data

Display and Analyze the Data Type(s) of graphs that would best represent the data Measures of center and spread Identify any outliers or irregularities in the data Interpret the data using percentages

Summarize the Results Indicate the main findings Are the results what you expected? Why or why not?