Week 9 - Explanatory Factor Analysis

Question 1

What are latent variables?

Answer 1

Things that can not be measured directly. Usually the focus of psychology researchers.

Question 2

What are the three main uses of factor analysis?

Answer 2

1. To understand the structure of a set of variables
2. To construct a questionaire to measure an underlying variable variable
3. To reduce a data set to a more manageable size while retaining as much of the original information as possible

Question 3

What is factor loading?

Answer 3

The regression coefficient of a variable for the linear model that describes a latent variable or factor in factor analysis.

Question 4

What are common factors?

Answer 4

A factor that affects all measured variables and, therefore, explains the correlations between those variables.

Question 5

What are unique factors?

Answer 5

A factor that affects only one of many measured variables and, therefore, cannot explain the correlations between those variables

Question 6

What is a factor matrix?

Answer 6

General term for the structure matrix in principal component analysis

Question 7

What are factor scores?

Answer 7

A single score from an individual entity representing their performance on some latent variable

Question 8

What is the Anderson-Rubin method?

Answer 8

A way of calculating factor scores which produce scores that are uncorrelated and standardized with a mean of 0 and a standard deviation of 1

Question 9

What is confirmatory factor analysis?

Answer 9

A version of factor analysis in which specific hypotheses about structure and relations between the latent variables that underlie the data are tested

Question 10

<p>What is common variance?</p>

Answer 10

Variance shared by two or more variables.

Question 11

What is unique variance?

Answer 11

Variance that is specific to a particular variable (not shared with other variables). We tend to use the term ‘unique variance’ to refer to variance that can be reliably attributed to only one measure otherwise it is called random variance.

Question 12

What is random variance?

Answer 12

Variance that is unique to a particular variable but not reliably so.

Question 13

What is communality?

Answer 13

The proportion of a variable’s variance that is common variance.

Question 14

What is a scree plot?

Answer 14

A graph plotting each factor in a factor analysis (x-axis) against its associated eigenvalue (y-axis). It shows the relative importance of each factor.

Question 15

What is Kaiser’s criterion?

Answer 15

A method of extraction in factor analysis based on the idea of retaining factors with associated eigenvalues greater than 1.

Question 16

What is rotation?

Answer 16

A process in factor analysis for improving the interpret-ability of factors. In essence, an attempt is made to transform the factors that emerge from the analysis in such a way as to maximise factor loadings that are already large, and minimise factor loadings that are already small.

Question 17

What is orthogonal rotation?

Answer 17

A method of rotation in factor analysis that keeps the underlying factors independent (not correlated)

Question 18

What is oblique rotation?

Answer 18

A method of rotation in factor analysis that allows the underlying factors to be correlated.

Question 19

What is the factor transformation matrix?

Answer 19

A matrix used in factor analysis. It can be thought of as containing the angles through which factors are rotated in factor rotation.

Question 20

What is the KMO?

Answer 20

The Kaiser-Meyer-Olkin measure of sampling adequacy. It is calculated to represent the ratio of the squared correlation between variables to the squared partial correlation between variables.

Question 21

What is the Bartlett’s test?

Answer 21

The test examines whether a variance - covariance matrix is proportional to an identity matrix. It effectively tests whether the diagonal elements of variance-covariance matrix are equal.

Question 22

What is singularity?

Answer 22

A term used to describe variables that are perfectly correlated.