Variability

Question 1

It provides a quantitative measure of the differences between scores in a distribution and describes the degree to which the scores are spread out or clustered together.

Answer 1

Variability

Question 2

3 Measures of Variability

Answer 2

1. Variance
2. Range
3. Standard Deviation

Question 3

The first step toward defining ad measuring variability which is the distance covered by the scores in a distribution.

Answer 3

Range

Question 4

The distance from the mean.

Answer 4

Deviation

Question 5

2 parts of Deviation score

Answer 5

1. Sign
2. Number

Question 6

It tells the direction from the means–that is, whether the score is located above or below the mean.

Answer 6

Sign

Question 7

It gives the actual distance from the mean.

Answer 7

Number

Question 8

It equals of the squared deviations and it is the average distance from the mean.

Answer 8

Variance

Question 9

It is the square root of the variance and provides a measure of the standard, or average distance from the mean.

Answer 9

Standard Deviation

Question 10

It is the sum of the squared deviation scores.

Answer 10

Sum of Squares (SS)

Question 11

2 formulas of SS

Answer 11

1. Definitional Formula
2. Computational Formula

Question 12

The first of SS’ formula where the symbols literally define the process of adding up the squared deviations.

Answer 12

Definitional Formula

Question 13

An alternative formula that has been developed for computing SS where it performs calculations with the scores and therefore minimizes the complications of decimals and fractions.

Answer 13

Computational Formula

Question 14

It is represented by the symbol σ2 and equals the mean squared distance from the mean and is obtained by dividing the sum of squares by N.

Answer 14

Population Variance

Question 15

It is represented by the symbol σ2 and equals the square root of the population variance.

Answer 15

Population Standard Deviation

Question 16

It is represented by the symbol s2 and equals the mean squared distance from the mean and is obtained by dividing the sum of squares by n-1.

Answer 16

Sample Variance

Question 17

It is represented by the symbol s and equal the square root of the sample variance.

Answer 17

Sample Standard Deviation

Question 18

It is often called sample variance.

Answer 18

Estimated Population Variance

Question 19

It is often called as sample standard deviation.

Answer 19

Estimated Population Standard Deviation

Question 20

It determines the number of scores in the sample that are independent and free to vary.

Answer 20

Degrees of Freedom (df)

Question 21

The classification of sample statistic if the average value of the statistic if equal to the population parameter.

Answer 21

Unbiased

Question 22

A classification of sample statistic if the average value of the statistic either underestimates or overestimates the corresponding population parameter.

Answer 22

Biased

Question 23

This term is used to indicate that the sample variance represents unexplained and uncontrolled differences between scores.

Answer 23

Error Variance

Question 24

3 situations to use Range

Answer 24

1. Sample sizes are similar
2. Small data sets
3. Skewed Distributions

Question 25

Formula of Deviation score

Answer 25

X - M

Question 26

Formula of Definitional Formula

Answer 26

SS= Σ(X - M)2

Question 27

Formula of Computational Formula

Answer 27

SS= ΣX2 - (ΣX)2/N

Question 28

Formula of Population Variance

Answer 28

o2 = SS/N

Question 29

Formula of Population Standard Deviation

Answer 29

o = √SS/N

Question 30

Formula of Sample Variance

Answer 30

s2 = SS/n - 1

Question 31

Formula of Sample Standard Deviation

Answer 31

s = √s2