Chapter 1: Introduction to Statistics

Question 1

What is statistics?

Answer 1

Statistics is a branch of mathematics used to summarize, analyze, and interpret a group of numbers or observations.

Question 2

What is a population?

Answer 2

A population is the set of all individuals, items, or data of interest. This is the group about which scientists will generalize.

Question 3

What are the two branchs of statistics?

Answer 3

Descriptive and inferential

Question 4

What is descriptive statistics?

Answer 4

Descriptive statistics are procedures used to summarize, organize, and make sense of a set of scores called data and are typically presented graphically, in tabular form (in tables), or as summary statistics (single values).

Question 5

What is inferential statistics?

Answer 5

Inferential statistics are procedures used that allow researchers to infer or generalize observations made with samples to the larger population from which they were selected.

Question 6

What is a sample?

Answer 6

A sample is a set of individuals, items, or data selected from a population of interest.

Question 7

What is an operational definition?

Answer 7

An operational definition is a description of some observable event in terms of the specific process or manner by which it was observed or measured.

Question 8

What are the three requirements for the experimental method?

Answer 8

Manipulation, randomization, comparison/control

Question 9

What is the quasi-experimental method?

Answer 9

A quasi-experiment is a study that (1) includes a quasi-independent variable and/or (2) lacks a comparison/control group.

Question 10

What is the correlational method?

Answer 10

The correlational method can determine whether a relationship exists between variables, but it lacks the controls needed to demonstrate cause and effect.

Question 11

What are scales of measurement?

Answer 11

Scales of measurement identify how the properties of numbers can change with different uses.

Question 12

What are the four scales of measurement?

Answer 12

Nominal, ordinal, interval, ratio

Question 13

What are nominal scales?

Answer 13

Nominal scales are measurements in which a number is assigned to represent something or someone.

Common examples of nominal numbers include ZIP codes, license plate numbers, credit card numbers, country codes, telephone numbers, and Social Security numbers.

Question 14

What are ordinal scales?

Answer 14

Ordinal scales are measurements that convey order or rank alone.

Examples of ordinal scales include finishing order in a competition, education level, and rankings.

Question 15

What are interval scales?

Answer 15

Interval scales are measurements that have no true zero and are distributed in equal units.

Examples include a rating scale and temperature.

Question 16

What are ratio scales?

Answer 16

A ratio scale is equidistant, has a true zero, and is the most informative scale of measurement.

Common examples of ratio scales include counts and measures of length, height, weight, and time.

Question 17

What is an independent variable?

Answer 17

An independent variable (IV) is the variable that is manipulated in an experiment.

Question 18

What is a dependent variable?

Answer 18

The dependent variable (DV) is the variable that is measured in each group of a study, and is believed to change in the presence of the independent variable.

It is the “presumed effect.”

Question 19

What is the quasi-experimental method?

Answer 19

A quasi-experiment is a study that (1) includes a quasi-independent variable and/or (2) lacks a comparison/control group.

In a typical quasi-experiment, the variables being studied cannot be manipulated, which makes random assignment impossible.

Question 20

What is a continuous variable?

Answer 20

A continuous variable is measured along a continuum at any place beyond the decimal point. A continuous variable can thus be measured in fractional units.

Time (in seconds), then, is a continuous variable.

Question 21

What is a discrete variable?

Answer 21

A discrete variable is measured in whole units or categories that are not distributed along a continuum.

For example, the number of brothers and sisters you have makes sense only when given in whole units or numbers

Question 22

What is a quantitative variable?

Answer 22

A quantitative variable varies by amount. This variable is measured numerically and is often collected by measuring or counting.

Question 23

What is a qualitative variable?

Answer 23

A qualitative variable varies by class. This variable is often represented as a label and describes nonnumeric aspects of phenomena.