8/12/2019 Statistics in Plain English, 3rd Ed - Chapter 1 Summary

1/3

8/12/2019 Statistics in Plain English, 3rd Ed - Chapter 1 Summary

2/3

i. ategorical (sometimes called *ualitative) A variable "ith independent

categories, such as gender or grade level.

ii. rdinal A variable for "hich the numbers are meaningful, but the intervals

bet"een the numbers are not e*ual, such as the place of finishing in a race.

iii. Interval/ratio A variable for "hich the numbers are meaningful and the intervalsbet"een the numbers are e*ual, such as "eights on a scale, hours, inches, etc.

c. +here is also a distinction bet"een independent and dependent variables.

i. $ependent +he values of this variable are presumed to depend on the values of

another variable.

ii. Independent +he values of the dependent variable are presumed to depend on the

value of the independent variable.

0. e.g., nergy level (dependent variable) can depend on ho" much sugar

one eats (independent variable).

-. 'esearch designs

a. +here are different types of research that employ different research designs.

b. !perimental +he researcher manipulates an independent variable to determine "hether

it influences the dependent variable.

c. 1uasi2e!perimental +he researcher manipulates an independent variable to determine

"hether it influences the dependent variable, but in a naturally occurring situation rather

than a controlled laboratory setting.

d. orrelational +he researcher does not manipulate independent variables but measures

t"o or more variables to see ho" they are associated "ith each other.

e. bservational/naturalistic +he researcher observe phenomenon as they occur in a natural

setting (e.g., a school, a business, a forest) and records the observations.

-I. 3raphs

a. $ata are often represented pictorially, in graphs.

b. +he purpose of the graph is to summari4e the information about a distribution in amanner that is clear and easy to comprehend.

c. +here are several "ays to graphically represent data. Some of the most common are line

graphs, column graphs, stac#ed column graphs, and pie charts.

8/12/2019 Statistics in Plain English, 3rd Ed - Chapter 1 Summary

3/3