Chapters 1-3

Question 1

Variable

Answer 1

is any characteristic of a person or thing that can be assigned a number or category.
Variables: are things that we measure, control, or manipulate in study.

Question 2

observational unit

Answer 2

The person or thing to which the number or category is assigned.

Question 3

Data

Answer 3

consist of the numbers or categories recorded for the observational unit.

Question 4

Variability

Answer 4

refers to the phenomenon of a variable taking on different values or categories from observational unit to observational unit.

Question 5

Quantitative Variable:

Answer 5

measures a numerical characteristic. Examples: Height, age, GPA, salary, temperature, area, volume, Any variable that is not quantitative is categorical.

Question 6

Categorical variables

Answer 6

take a value that is one of several possible categories. As naturally measured, categorical variables have no numerical meaning.
Examples: Hair color, gender, field of study, political affiliation, status of disease infection.

Question 7

Binary variables

Answer 7

are categorical variables which only two possible categories. Example: yes – no, Male/F

Question 8

Research question:

Answer 8

looks for patterns in a variable,
compares a variable across different groups
looks for a relationship between variables.

Question 9

Summary

Answer 9

A variable is a characteristic that varies from person to person or from thing to thing. The person or thing is called an observational unit.
Variables can be classified as categorical or quantitative.
A categorical variable with only two possible categories is called binary.

Question 10

Distribution:

Answer 10

refers to the representation of the data. Pattern of variability of the data.

Question 11

Dotplot

Answer 11

consists of a graph in each data value is plotted as a point (or dot) along a scale of values. It is useful for displaying the distribution of relatively small datasets of a quantitative variable.

Question 12

Bar graph:

Answer 12

display the distribution of a categorical variable.

Question 13

parameter:

Answer 13

numerical measurement of characteristics of a population.

Question 14

Statistic:

Answer 14

numerical measurement of characteristics of a sample.

Question 15

Explanatory variable:

Answer 15

is the variable whose effect you want to study

Question 16

Response variable:

Answer 16

the variable that you suspect is affected by the other variable

Question 17

observational study

Answer 17

observes individuals and collect specific characteristics (variables on interest) but not attempt to modify the subjects being studies

Question 18

Drawing Conclusions from Studies

Answer 18

observational study: you can not draw a cause-and –effect conclusion between the explanatory variable and response variable.

Question 19

A Confounding variable

Answer 19

is one whose effect on the response variable cannot be distinguished from the effect of the explanatory variable.