Exploratory factor analysis

Question 1

What is a concept?

Answer 1

an abstraction of some sort of idea or phenomenon

Question 2

What is a variable?

Answer 2

Something that can take on different values

Question 3

What are different forms of validity?

Answer 3

• content validity
• construct validity
• face validity
• statistical conclusion validity

Question 4

What is reliability?

Answer 4

the extent to which a measurement produces consistent results when repeated. All measurements are subject to random error. A measurement with low random error has high reliability.

Question 5

What is exploratory factor analysis?

Answer 5

a class of procedures used for data reduction and summarization. is very important when questionnaire surveys are used

Question 6

When is factor analysis used?

Answer 6

• to identify underlying dimensions, or factors that explain the correlations among a set of indicators
• to identify the factors that make up the variables for hypothesis testing

Question 7

Designing a factor analysis requires a minimum of sample size. What is the minimum?

Answer 7

100 samples (5 observations per variable)

Question 8

What is a correlation matrix?

Answer 8

a lower triangle matrix showing the simple correlations, r, between all possible pairs of variables included in the analysis

Question 9

What is Bartlett’s test of sphericity?

Answer 9

its a test of the null hypothesis that the variables are uncorrelated: so its a test of non-normal sample distributions

Question 10

What is communalities?

Answer 10

amount of variance a variable shares with all other variables

Question 11

What is Kaiser-Meyer-Olkin measure of sampling adequacy?

Answer 11

it explains how much one item’s variance overlaps with another item’s variance

Question 12

What is Eigenvalue?

Answer 12

it represents the total variance explained by each factor

Question 13

What is factor loadings?

Answer 13

correlations between the variables/the factors

Question 14

When do we have construct validity?

Answer 14

When we have Convergent validity and Discriminant validity

Question 15

What does it mean if we say that correlation = good?

Answer 15

variables correlate with what they should (convergent) and what they should not (discriminant)

Question 16

How should the bivariate correlation matrix look like in an exploratory factor analysis?

Answer 16

we want HIGH correlations with a construct of LOW between independent constructs/variables

Question 17

What is commonalities?

Answer 17

they represent the extent to which an item correlates with all other items. Should be above 0.50. if they are not, remove them and re-run the analysis. but above 0.7 is what we strive for

Question 18

What is the Kaiser-Meyer-Olkin Measure of Sampling adequacy? (KMO)

Answer 18

KMO explains how much one item/variables variance overlaps with another item/variables variance. Value should be above 0.50

Question 19

Why is KMO used?

Answer 19

It is used to test how suited data is for factor analysis

Question 20

What is rotation? (in EFA)

Answer 20

any of several methods in factor analysis by which the researcher attempts to relate the calculated factors to the theoretical entities

Question 21

What are the two basic types of rotation to choose from in EFA?

Answer 21

1. orthogonal (assume uncorrelated factors)
2. oblique (assume correlated factors)

Question 22

Factor loadings should be above what number?

Answer 22

above 0.50.

Question 23

Correlation should be above what number?

Answer 23

above 0.30

Question 24

What is the anti-image correlation?

Answer 24

the measure of KMO for each indicator/variable is given in the diagonal. in the diagonal, items with value under 0.5 should perhaps be deleted

Question 25

What is one of the most accepted methods to test Reliability?

Answer 25

Coefficient Alpha (Chronbach’s Alpha test). it tests how well the items in each variable relate to each other.

in general, the cutoff value is above 0.7 and accepted for the Chronbachs Alpha. (shows reliable variable)