Jerusha was very excited. She was sure she would do well on thisproject, because it did not involve problem solving.
Ms. Smith explained all thedifferent types of surveys used to analyze data.
First she explained biased surveys. “A biased survey is a when one doesn’t include the opinion of part of the population. For example, if Istood in front of L’Occitane, and asked people coming out of L’Occitane what their favorite brand of hand cream was, that would be biased, because they like L’Occitane hand cream. If they don’t, why are werethey in L’Occitane? Ms. Smith raised her voice at this point to tell the class something. “You are not to have a biased sample as part of your project, class!”
Jerusha, who found this very uninteresting, was daydreaming about how she would receive herfirst A in math, because she would do so well on this project. So,instead of hearing you are NOT to have a biased sample, heard you ARE to have a biased sample.
Ms. Smith went on to tell the class about representative samples (a small sample whose characteristics represent the entire population’s), random samples (a sample selected on the basis of pure chance in situations free of any bias), and convenience samples (a sample when the population ischosen at the convenience of the researcher).
After school one day she stood outsideDuane Reade, asking everyone coming out to fill out her survey about their favorite shampoo brands. “This is such a biased survey!” she thought.
But it wasn’t. Jerusha didn’t knowthis. She had a representative sample,because Duane Reade isn’t focused onone brand of anything. They have a lot of different choices. So, Jerusha was doing something right, but she didn’t even know.
When the time came to hand in herproject, Jerusha was very nervous, but she was also excited.
So was her teacher, because Jerusha had finally earned an A.
When Jerusha showed her mother her project, her mother was alsovery proud. But she did have one question.
“Jerusha, I thought you said you had to have a biased sample!”