Chapter 7 summering and interpreting data

Question 1

Sampling error

Answer 1

The difference between the observation in a population and in the sample that represents that population in a study

Question 2

Descriptive statistics

Answer 2

Measure that help us summarize data sets

Question 3

Inferential statistics

Answer 3

A set of statistical procedures used by researchers to test hypotheses about population

Question 4

Distribution

Answer 4

A set of scores

Question 5

Central tendency

Answer 5

Representation of a typical score in a distribution

Question 6

Variability

Answer 6

The spread of scores in a distribution

Question 7

Mean

Answer 7

The calculated average of the scores in a distribution

Question 8

Median

Answer 8

The middle score in a distribution, such that half of the scores are above and half are below the value

Question 9

Mode

Answer 9

The most common score in a distribution

Question 10

Outliners

Answer 10

Extreme high or low scores in the distribution

Question 11

Reaction time

Answer 11

Measurement of the length of time to complete a task

Question 12

Range

Answer 12

The difference between the highest and the lowest score in a distribution

Question 13

Standard deviation

Answer 13

A measure representing the average difference between the scores and the mean of a distribution

Question 14

Variance

Answer 14

The standard deviation of a distribution squared

Question 15

Degrees of freedom

Answer 15

Number of scores that can vary in the calculation of a sadistic

Question 16

Frequency distribution

Answer 16

A graph of a distribution showing the frequency of each response in the distribution

Question 17

Bar Graph

Answer 17

A graph of the means for different conditions in a study where the bar height represents the size of the mean

Question 18

Line graph

Answer 18

A graph of the means for different conditions in a study where each mean is graphed as a point and the points are connected in a line to show differences between mean scores

Question 19

Scatterplot

Answer 19

A graph showing the relationship between two dependent variables for a group of individuals

Question 20

Predictor variable

Answer 20

The dependent variable in a correlational Study that is used to predict the score of another variable

Question 21

Outcome variable

Answer 21

The dependent variable in a correlational study that is being predicted by the predictor variable

Question 22

Scientific/alternative hypothesis

Answer 22

Hypothesis that in effect or relationship exist ( or exists in a specific direction) in the population

Question 23

Null hypothesis

Answer 23

The hypothesis that an effect or relationship does not exist ( or exists in the opposite direction of the alternative hypothesis) in a population

Question 24

Two-tailed hypothesis

Answer 24

Both directions of an effect or relationship are considered in the alternative hypothesis of the test

Question 25

One-tailed hypothesis

Answer 25

Only one direction of an effect or relationship is predicted in the alternative hypothesis of the test

Question 26

Distribution of sample means

Answer 26

The distribution of all possible sample means for all possible samples from a population

Question 27

Confidence intervals

Answer 27

A range of values that the population mean likely falls into with a specific level of certainty

Question 28

Alpha level

Answer 28

The probability level used by researchers to indicate the cut off probability level (highest value) that allows them to reject the null hypothesis.

Question 29

P value

Answer 29

Probability value associated with an inferential test that indicates the likelihood of obtaining the data in a study when the null hypothesis is true

Question 30

Significant test

Answer 30

The P value is less than or equal to Alpha In an inferential test, and the null hypothesis can be rejected

Question 31

Critical region

Answer 31

The most extreme portion of a distribution Of statistical values for the null hypothesis determined by the alpha level (typically 5%)

Question 32

Type l error

Answer 32

Error made in a significance test when the researcher rejects the null hypothesis when it is actually true

Question 33

Type II error

Answer 33

Error made in a significance test when the researcher fails to reject the null hypothesis when it is actually false

Question 34

Power

Answer 34

Ability of a significance test to detect an effect or relationship when one exists ( equal to 1- the probability of a type II error)