Chapter 3

Question 1

Z score

Answer 1

number of standard deviations that a score is above (or below, if it is negative) the mean of its distribution; it is thus an ordinary score transformed so that it better describes the score’s location in a distribution.

Question 2

raw score

Answer 2

ordinary score (or any number in a distribution before it has been made into a Z score or otherwise transformed.

Question 3

Normal distribution

Answer 3

Frequency distribution that follows a normal curve.

Question 4

Normal Curve

Answer 4

Specific, mathematically defined, bell-shaped frequency distribution that is symmetrical and unimodal; distributions observed in nature and in research commonly approximate it.

Question 5

Normal Curve Table

Answer 5

Table showing percentages of scores associated with the normal curve; the table usually includes percentages of scores between the mean and various numbers of standard deviations above the mean and percentages of scores more positive than various numbers of standard deviations above the mean.

Question 6

Population

Answer 6

Entire group of people to which a researcher intends the results of a study to apply; larger group to which inferences are made on the basis of the particular set of people (samples) studied.

Question 7

Sample

Answer 7

Scores of the particular group of people studied; usually considered to be representative of the scores in some larger population.

Question 8

Random Selection

Answer 8

Method for selecting a sample that uses truly random procedures (usually meaning that each person in the population has an equal chance of being selected); one procedure is for the research to begin with a complete list of all the people in the population and select a group of them to study using a table of random numbers.

Question 9

Population parameters

Answer 9

Actual value of the mean, standard deviation, and so on, for the population; usually population parameters are not known, though often they are estimated based on information in samples.

Question 10

μ
𝜇

Answer 10

population mean.

Question 11

σ2

Answer 11

population variance

Question 12

σ

Answer 12

population standard deviation

Question 13

Sample Statistics

Answer 13

Descriptive statistics, such as the mean or standard deviation, figured from the scores in a group of people studied.

Question 14

Probaility

Answer 14

Expected relative frequency of an outcome; the proportion of successful outcomes to all outcomes.

Question 15

Outcome

Answer 15

Term used in discussing probability for the result of an experiment (or almost any event, such as a coin coming up heads or it raining tomorrow.

Question 16

Expected Relative Frequency

Answer 16

Number of successful outcomes divided by the number of total outcomes you would expect to get if you repeated an experiment a large number of times.