Elementary Terms
More Vocab
What is my scale of measure?
Type of Study
Sampling Techniques
100

The official count of a population

Census

100

a subset of the population

Sample
100

Colors of cars in the parking lot

Nominal

100

People should brush their teeth at least twice a day for at least two minutes with each brushing. For a class project, you ask a random number of students at your school questions concerning their tooth-brushing habits

Survey

100

Ask the first 20 people seen carrying mineral water in a park on a summer day

Systematic

200

A characteristic of interest for the elements

Variable

200

A number that describes the whole population

Parameter
200

Daily temperature in Ephrata, PA

Interval

200

The local Dept. of Transportation is responsible for maintaining lane and edge lines on its paved roads. There are two new paint products on the market. Twenty comparable stretches of road are identified. Paint A is randomly assigned to ten of the stretches of road and Paint to the other ten. The department finds that Paint lasts longer.

Observational Study

200

Ask your friends

Convenience Sampling

300

A science that consists of collecting, organizing, analyzing, and interpreting data

Statistics

300

The group in an experiment that does not receive the experimental treatment

Control Group

300

A restaurant rating (A, B, C, D, F)

Ordinal

300

The National Highway Traffic Safety Administration conducts annual studies on drivers' seatbelt use at a random selection of roadway sites in each state in the US. To determine if seatbelt usage has increased, data are analyzed over two successive years. 

Observational Study

300

Student ID numbers are randomly selected by a computer for a survey of student opinions on college athletics.

Simple Random Sampling (SRS)

400

Using observations from a sample to draw conclusions about a population

Inferential Statistics/Inferencing

400

A zero that implies "none"

Inherent Zero

400

The amount of money spent at the War Memorial Field Burger Shack at last week's football game.

Ratio

400

A television network mails a questionnaire to randomly selected people across the country to determine whether they prefer watching sitcoms or dramas.

Survey
400

Part of the research plan calls for describing and comparing the opinions of four different ethnic groups. For a total sample of 300, the researcher selects 75 participants from each of the four predetermined subgroups.

Stratified Sampling

500

Repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding extends to other participants and circumstances

Replication

500

Any individual associated with an experiment who is not aware of how subjects have been allocated to treatment groups

Blinding/Blinded

500
Credit card numbers of people in your family

Nominal

500

An engineer is planning to test 50 metal samples to determine whether a new titanium alloy has a higher strength than a different alloy.

Experiment

500

A sample of 2,000 was sought to estimate the average achievement in science of fifth graders in a city’s public schools. The average fifth grade enrollment in the city’s elementary schools is 100 students. Thus, 20 schools were randomly selected and within each of those schools all fifth graders were tested.

Cluster Sampling

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