Survey
A survey collects data from a sample — a smaller, representative subset — to make inferences about a larger population without gathering data from every individual. In Grade 6 Saxon Math Course 1, students learn that the population is the entire group of interest and the sample is the portion actually surveyed. For a school of 500 students, surveying a random sample of 50 saves time while still giving useful information. For survey results to be valid, the sample must be selected randomly to avoid bias.
Key Concepts
Property A survey is a way of collecting data about a population. Rather than collecting data from every member of a population, a survey might focus on only a small part of the population called a sample .
Examples To find the most popular movie in school, you survey $50$ students (the sample) instead of all $500$. A TV network asks $1,000$ viewers if they like a new show to decide if it should be renewed for another season. A company gives free cookie samples at a store to predict if the new flavor will be a bestseller nationwide.
Explanation A survey is like tasting a tiny spoonful of soup to know if the whole pot is delicious. You can't ask everyone in the country their favorite ice cream, so you ask a smaller group (a sample) instead. By studying the sample's answers, you can make a pretty good guess about what the entire population thinks without doing all that work!
Common Questions
What is a survey?
A method of collecting data by asking questions of a selected group (the sample) to learn about a larger group (the population).
What is the difference between population and sample?
The population is the entire group you want information about; the sample is the smaller group you actually collect data from.
Why survey a sample instead of the whole population?
It saves time and resources while still providing useful information about the population, provided the sample is representative.
What makes a survey biased?
A biased survey uses a non-random or non-representative sample. For example, surveying only students in an advanced class to represent all students is biased.
What is a random sample?
A sample where every member of the population has an equal chance of being selected, reducing the likelihood of bias.