AP Statistics Unit 3 Vocab Terms

Sampling data, random variability, responses, and bias

Stratified Random Sample

A school wants fair representation of each grade in a cafeteria food survey, so students are grouped by grade before random selection. What sampling method is this?

Generating Conclusions Based on Studies

A company wants to test a new snack. They randomly select 50 employees and then generalize results to all customers. Drawing broad claims from this study is an example of what process?

Treatments

A farmer compares apple yield from trees treated with three different fertilizers. The fertilizers are examples of what?

Experimental Units

A psychologist tests whether meditation improves focus by measuring the performance of students in different groups. The students themselves are what?

Response Variable

A nutritionist runs an experiment where participants eat different diets, and she measures their blood sugar afterward. The blood sugar measurement is what?

Control Group

A drug study has some patients receive a placebo pill instead of the real medication. These patients belong to what group?

Control

In a medical experiment, all participants get the same exercise and diet plan, except for the treatment being studied. What is this principle called?

Sampling Method Bias

A teacher only surveys students sitting at the front of the class, leading to skewed results. This is an example of what?

Stratification

A researcher divides students by gender before sampling, to ensure representation of both males and females. The act of separating into subgroups before sampling is what?

Simple Random Sample

A lottery system randomly chooses 100 people from a population of 10,000, where each person has an equal chance of being chosen. What sampling method is this?

Cluster Sample

A principal randomly selects 4 classrooms and surveys every student in those classrooms. What sampling method is this?

Systematic Random Sample

A researcher surveys every 10th name on the school roster. What sampling method is this?

Undercoverage

A poll surveys only students in the library at lunch, missing those elsewhere. What type of problem does this illustrate?

Bias

A survey only asks volunteers to respond online, and only those who feel strongly participate. This introduces what?

Convenience Sample

A teacher hands surveys to only the students walking by her classroom after school. What sampling method is this?

Voluntary Response Sample

A radio host asks listeners to call in if they have opinions on a new law. What sampling method is this?

Sampling Variability

A teacher surveys two different random groups of students and gets slightly different average results each time. What explains this difference?

Sampling Frame

A pollster uses a list of registered voters to contact people for a political survey. The list itself is called what?

Population

A researcher studies 200 randomly chosen city residents and then generalizes results to all residents of the city. The entire city population represents what?

Sample

In that same city survey, the 200 people actually chosen and studied represent what?

Simple Random Assignment

A teacher flips a coin to assign each student to one of two review methods before a test. What process is this called?

Blocking

A doctor tests two medications but groups patients first by age before randomly assigning treatments. What is this method called?

Observational Study

A nutritionist observes how much junk food high school students eat without changing their behavior. What kind of study is this?

Single-Blind

In a drug trial, patients don’t know whether they’re receiving the actual drug or a placebo, but the doctors do. What design is this?

Double-Blind

In another drug trial, neither patients nor doctors know who receives the real drug versus the placebo. What design is this?

Placebo Effect

In a drug trial, some patients who receive a sugar pill still report feeling better, even though the pill had no active ingredients. What effect is this?

A researcher tests whether exercise improves grades, but students who exercise also tend to eat healthier. This extra factor makes it unclear what caused the better grades. What is this problem called?