WK 11 Flashcards
How do you interpret the meaning of the factors?
Based on the size and the sign of the loadings that you deem to be salient
In most research, what are salient loadings?
salient loadings are greater than or equal to |0.3| or |0.4|
What is a salient relationship?
Salient relationship = big enough relationship for us to be interested in
(It is of a signifcant size that we would note and retain in our analysis)
What do we do if we see an item that does not load on any factor above this salient value of 0.3?
We would deem it as one that isn’t being explained well or accounted for by our factor solution, and ear mark it as one we may remove from our analysis
What is a heywood case?
factor loadings > 1
What does a Heywood case tell you?
tells you there is a problem in the analysis
If a factor does not have a primary loading from at least 3 items that you are analysing, what do you do?
We query basically whether we have done this over-extraction
What loading criteria is in place for EFA solutions?
All factors load on 3+ items at salient level
What is the EFA criteria for the items?
All items have at least one loading above salinet cut off
What is the EFA criteria for heywood cases?
No heywood cases
What is the EFA criteria for complex items?
Complex items removed in accordance with goals
What is the EFA criteria for item content?
Item content of factors is coherent and substantively meaningful
What is one way to test replicability?
One way to test replicability is to see whether similar factors appear when similar data are collected
Aside from similarity checks, what is another way of testing replicability?
Test this formally by collecting data on another sample or split one large sample into two (exploratory vs confirmatory)
What is factor congruence?
It is a way of saying if I look across samples, how consistent is the factor solution I identify
What does factor congruence enable?
It enables us to look at similarity of solutions
What is congruence coeffiecents?
Essentially correlations between factor loadings stacked on top of each other
What is confirmatory factor analysis?
This tests the model where we explicitly say that this item has to relate with this factor -> We specify the grouping
- it is not driven by data
What is target rotation?
Target rotation is where you give the rotation algorithm, what items should relate to what factors (give it a structure)
What does it mean when the congruence coefficient is 1?
It suggests that there’s a perfect match between the factor solutions.
If the loading is comparatively high in one sample and comparatively high in the other, what do this mean?
that’s going to lead to a higher correlation because basically the rank is roughly the same.
In confirmatory factor analysis what do we do?
We specify a model and test how well it fits the data
How do we specify a model in CFA?
We specify a model by indicating what loadings we believe will be zero -> we then try to reject this model
What does it mean if the correlations derived from the CFA do not match the correlations from your data?
It probably means that parameters set to zero should not have been set to zero
What do you do in unit-weighting?
You sum raw scores on the observed variables which have primary loadings on each factor
What items do you sum in unit-weighting?
Which items to sum is a matter of defining what loadings are salient
What do Thurstone or Thompson method do?
They compute scores from observed item correlations and loadings (weighted method of producing scores)
What does Bartlett method focus on?
Focuses on minimizing the sums of squares for unique factors