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Flashcards in Chapter 4 (2) Deck (22):
1

An _____ _____ observes individuals and measures variables of interest but does not attempt to influence the responses

Observational study

2

An ______ deliberately imposes some treatment on individuals to measure their responses

Experiment

3

When our goal is to understand cause and effect, ____ are the only source of fully convincing data

Experiments

4

A ______ _______ is a variable that is not among the explanatory or response variables in a study but that may influence the response variables

Lurking variables

5

_______ is when the effects of two variables on the response variable can not be separated from each other

Confounding

6

A specific condition applied to the individuals in an experiment is called a ______

Treatment

7

The _______ _____ are the smaller collection of individuals to which treatments are applied

Experimental units

8

When experimental units are human beings, they are often called _____

Subjects

9

The explanatory variables in an experiment are called ____

Factors

10

Badly designed experiments often yield worthless results because of ______

Confounding

11

Most well-designed experiments compare two or more ______

Treatments

12

_____ _________ means that experimental units are assigned to treatments at random, using some sort of chance process

Random assignment

13

The primary purpose of a ___ ____ is to provide a baseline for comparing the effects of the other treatments

Control group

14

The three basic principles of experimental design are _____, ___ ______, and ________

Control, random assignment, replication

15

_____ lurking variables that might affect the response

Control

16

______ _______ uses impersonal chance to assign experimental units to treatments

Random assignment

17

______ uses enough experimental units in each group that differences in the effects of treatments can be distinguished from chance differences

Replication

18

Response to a dummy treatment, usually a psychological effect is called the ___ ____

Placebo effect

19

In a ____-____ experiment, neither the subjects nor those who interact with them and measure the response variable know which treatment a subject received

Double- blind

20

An observational fact so large that is would rarely occur by chance is called ______ _______

Statistically significant

21

A second form of control is to form ____ of individuals that are similar in some way important to the response

Blocks

22

________ ____ is a separate form of blocking for compared just two treatments

Matched pairs