Statistics Modules Vocab

Question 1

Standard error of the mean

Answer 1

the standard deviation of a sampling distribution of the mean.

Question 2

Degrees of freedom

Answer 2

the number of values in the final calculation of a statistic that are free to vary. The number of independent ways by which a dynamic system can move, without violating any constraint imposed on it, is called number

Question 3

Dispersion

Answer 3

how stretched or squeezed a distribution (theoretical or that underlying a statistical sample) is

Question 4

Type I error

Answer 4

rejecting the null hypothesis when, in fact, the null hypothesis is true.

Question 5

Type II error

Answer 5

failing to reject the null hypothesis when, in fact, the null hypothesis is false.

Question 6

p-value

Answer 6

the probability of obtaining an effect as extreme as results given that the null hypothesis is true

Question 7

Critical Region

Answer 7

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Question 8

t-test

Answer 8

an inferential statistical test often used to determine whether there is a statistically significant difference between the means of two groups of scores for the same variable.

Question 9

t-test for independent samples

Answer 9

compares the means between two unrelated groups on the same continuous, dependent variable

Question 10

paired-samples t-test

Answer 10

compares two means that are from the same individual, object, or related units

Question 11

analysis of variance (ANOVA)

Answer 11

collection of statistical models used to analyze the differences among group means and their associated procedure

Question 12

chi-square

Answer 12

n

Question 13

Power

Answer 13

probability of rejecting the null hypothesis when alternative is true

Question 14

Exploratory data analysis

Answer 14

analyzing data sets to summarize their main characteristics, often with visual methods - enables seeing what the data can convey

Question 15

Bar graph

Answer 15

a diagram in which the numerical values of variables are represented by the height or length of lines or rectangles of equal width.

Question 16

Line graph

Answer 16

uses line segments to connect data points and shows changes in data over time.

Question 17

Scatter plot

Answer 17

a graph in which the values of two variables are plotted along two axes, the pattern of the resulting points revealing any correlation present.

Question 18

Pie graph

Answer 18

n

Question 19

Frequency distribution

Answer 19

table that displays the frequency of various outcomes in a sample

Question 20

Histogram

Answer 20

graphical representation of the distribution of numerical data; estimate of the probability distribution of a continuous variable

Question 21

Skewed distribution

Answer 21

A distribution is negatively skewed, or skewed to the left, if the scores fall toward the higher side of the scale and there are very few low scores.

Question 22

Normal distribution

Answer 22

a function that represents the distribution of many random variables as a symmetrical bell-shaped graph.

Question 23

Outlier

Answer 23

an observation point that is distant from other observations. May be due to variability in the measurement or it may indicate experimental error

Question 24

Resistant measure

Answer 24

n

Question 25

Measure of central tendency

Answer 25

n

Question 26

Measure of spread

Answer 26

n

Question 27

Interquartile range

Answer 27

n

Question 28

Boxplot

Answer 28

n

Question 29

Phi coefficient

Answer 29

n

Question 30

Linear regression

Answer 30

n

Question 31

Least-square regression line

Answer 31

n

Question 32

Regression weight

Answer 32

n

Question 33

Correlation matrix

Answer 33

used to investigate the dependence between multiple variables at the same time. The result is a table containing the correlation coefficients between each variable and the others.