Definitions
A subset of a population used for research
What is a Sample?
A market researcher surveys 85 people on their coffee-drinking habits. She wants to know whether people in the local region are willing to switch their regular drink to something new. The sample is...
What is "the 85 people surveyed"?
The sampling method in which the easiest group to get data from is used
What is convenience sampling?
The head chef of a restaurant wants to know if he should add more vegetarian options to his menu. To find out the demand for vegetarian dishes amongst his customers, he sends out an email to everyone on the mailing list of the restaurant asking them to fill out a survey.
What is convenience Sampling?
A class of first graders is asked their favorite color. Is this data qualitative or quantitative?
What is qualitative data?
All members of a group that you are looking to make generalizations about.
What is a Population?
The state Department of Transportation wants to know about out-of-state vehicles that pass over a toll bridge with several lanes. A camera installed over one lane of the bridge photographs the license plate of every tenth vehicle that passes through that lane. The population is...
What is "all of the vehicles that pass through"?
The sampling method in which the sample is chosen randomly from the population.
What is Simple Random Sampling?
An elementary school principal wants to know more about how the car riders are dismissed. She surveys car riders from the following: girls from 4 grade and the boys from 5th grade.
What is stratified Sampling?
A class of first grade students is asked how many pets they have. Is this data qualitative or quantitative?
What is quantitative
A selection process in which every item has an equal probability of being chosen.
What is random?
A factory overseer selects 40 threaded rods at random from those produced that week at the factory, then she tests their tensile strength. The sample is...
What is "the 40 threaded rods selected"?
The sampling method in which the population is divided into subgroups?
What is Stratified Sampling?
A university wants to find out how far the average student lives from the campus. To investigate this matter, a random number generator is used to select a sample of 250 students from the student registry.
What is Simple Random Sampling?
A chart shows weights of sumo wrestlers at a tournament. How can you classify the data collected?
Continuous qualitative
A sample where you first divide your population into subgroups, then randomly pick people from each subgroup.
What is a stratified sample?
The owners of a sports stadium wanted to predict what additional refreshment options would sell well. They selected 8000 seat numbers at random and surveyed the occupants of those seats. The population is...
What is "the occupants of all seats in the stadium"?
The sampling method where the population is divided into groups and all the people in some of those groups are used.
What is Cluster Sampling?
In order to gather data about children's growth, 5 states are chosen at random and the heights of all the five year olds in those states is gathered.
What is Cluster Sampling?
A group of retired adults is asked how many cars they own. What term best describes the data collected.
Discrete quantitative
A sample that is NOT representative of the population it was drawn from.
What is a Biased Sample?
A city council member wanted to know how her constituents felt about a planned rezoning. She randomly selected 700,575 names from the city phone directory and conducted a phone survey. The sample is...
What is "the 700,575 people selected"?
A sample where a rule is used to select members of the population. (every nth person is selected)
What is Systematic Sampling?
You want to find out what each students' favorite subject is. You divide a school population into groups based on grade level and then create a sample by randomly selecting students from each grade level.
What is Stratified Random Sampling?
A librarian wants to know how many books high school students read over the summer. He asks all the students in an AP literature class how many books they read. Is this a representative sample?
No