Chapter 4 & 5

Question 1

Central tendency

Answer 1

descriptive statistic that best represents the center of a dataset, which is the “typical” score or value that the rest of the data is clustered around

Question 2

Statistics

Answer 2

numbers based on samples taken from a population

Question 3

Parameters

Answer 3

numbers based on whole populations

Question 4

Unimodal

Answer 4

when a distribution of scores has one mode

Question 5

Bimodal

Answer 5

when a distribution of scores has two modes

Question 6

Multimodal

Answer 6

when a distribution has more than two modes

Question 7

Variability

Answer 7

numerical way of describing how much spread there is in a distribution

Question 8

Variance

Answer 8

average of squared deviations from the mean

Question 9

Deviation

Answer 9

amount that a score in a sample differs from the mean of a sample

Question 10

Sum of squares

Answer 10

sum of each score’s squared deviation from the mean

Question 11

Standard deviation

Answer 11

square root of the variance; typical amount that each score varies from the mean

Question 12

Random sample

Answer 12

every member of the population has an equal chance of being selected into the study

Question 13

Convenience sampling

Answer 13

uses participants who are readily available

Question 14

Generalizability or external validity

Answer 14

researcher’s ability to apply findings from one sample or in one context to other samples or contexts

Question 15

Replication

Answer 15

duplication of scientific results, ideally in a different context or with sample that has different characteristics (aka reproducibility)

Question 16

Volunteer or self-selected sample

Answer 16

convenience sample in which participants actively choose to participate in a study

Question 17

Crowdsourcing

Answer 17

when a research team solicits input from a very large group of people, usually online

Question 18

Constraints on generality (COG) statement

Answer 18

a statement of the target population to which the study results should generalize which should be included in papers

Question 19

Confirmation bias

Answer 19

unintentional tendency to pay attention to evidence that confirms our beliefs rather than those that disconfirm

Question 20

Illusory correlation

Answer 20

phenomenon of believing one sees an association between variables when it doesn’t exist

Question 21

Personal or subjective probability

Answer 21

a person’s own judgement about the likelihood that an event will occur

Question 22

Expected relative-frequency probability

Answer 22

likelihood of an event occuring based on the actual outcome of many, many trials; only works in the long-run

Question 23

Outcome

Answer 23

result of a trial

Question 24

Success

Answer 24

outcome for which we’re trying to determine the probability

Question 25

Probability vs. proportion

Answer 25

probability is what we would expect in the long-run while proportions are what we observe

Question 26

Control group

Answer 26

level of IV that does not receive the treatment of interest in the study

Question 27

Experimental group

Answer 27

level of IV that receives treatment or intervention of interest

Question 28

Type 1 error

Answer 28

when we reject the null hypothesis but it is correct

Question 29

Type 2 error

Answer 29

when we fail to reject the null hypothesis but it is false