1 a latent variable model. 2 grace keeley 2006 ecol apps example: observed variable model
DESCRIPTION
3 How do we create a latent variable? (1) First, use this tool to draw an ellipse, representing a latent variable. (2) To name it, right click on the ellipse, select “object properties”, and name it “Land”.TRANSCRIPT
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A Latent Variable Model
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Grace & Keeley 2006 Ecol Apps Example: Observed Variable Model
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How do we create a latent variable?
(1) First, use this tool to draw an ellipse, representing a latent variable. (2) To name it, right click on the ellipse, select “object properties”, and name it “Land”.
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How do we create a latent variable? (cont.)
(3) Select this tool and click it on Land once to create a single indicator.
(4) You can open and drag from the list of variables the variable coastran, which is our indicator for Land.(5) Remember, you still need to
name the error for coastran!
default weight from latent to indicator is set at 1 for single indicator.
path from error to indicator set to 1.
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How do we create a latent variable? (cont.)
(6) Keep in mind that if a latent variable is endogenous, it will need its own error variable (Le1 in this case).
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Grace & Keeley 2006 Example with Latent Variables
We are now modeling interactionsamong latent variables.
Each LV has an indicator andeach indicator has an error.
Endogenous LVs haveprediction errors.
Indicator errors have beenset to zero (i.e., there isno measurement error).
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Grace & Keeley 2006 Example w/ LVs - Results
Results are identical to thosefrom the observed variablemodel.
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Grace & Keeley 2006 Example with Measurement Error
Measurement errorspecified in raw units.
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Grace & Keeley 2006 Example with ME - Results
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Comparison of Results
Can you find the main differences?