Moderated mediation: conditional IDEs syntax

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Błażej Mroziński

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Feb 20, 2019, 6:45:16 AM2/20/19
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Greetings,

I'd like to ask you for some guidance in specifying properly a mediated moderation model in lavaan.

Following Hayes PROCESS macro templates i'm setting model 14:

X is experimental condition coded as 0 - 1, V, M and Y are all continues (mean scores of discrete questionnaire items).

I mean centered all but Y, computed a product of M * V and now I'd like to code all the effects.

mod14 <- '
M ~ a*X
Y ~ c*X + b*M + V + MV

indirect:= a * b
direct := c
total := c + (a*b)'


What I'd like to add here is what output from PROCESS macro calls:
  • Conditional effects of the focal predictor at values of the moderator(s):
  • Conditional effect of focal predictor at values of the moderator
  • Conditional indirect effects of X on Y
  • Index of moderated mediation
I woud appreciate some help,
Thank you

Błażej Mroziński

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Feb 20, 2019, 7:19:30 AM2/20/19
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Following hints found here

I came up with this syntax:

mod14 <- '
M ~ a*X
Y ~ c*X + b*M + b2*V + b*MV


indirect:= a * b
direct := c
total := c + (a*b)

ab3 := a * b3 #index of moderated mediation?
lowV := a * b1 + ab3 * -0.5
highV := a * b1 + ab3 * 0.5
'

Would this be correct?

'

Terrence Jorgensen

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Feb 21, 2019, 3:28:10 PM2/21/19
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Would this be correct?

You need to label b1 and b3 correctly in your syntax, and put parentheses around the added terms that make up the simple slope of the b path.

a * (b1 + ab3 * -0.5)

Terrence D. Jorgensen
Assistant Professor, Methods and Statistics
Research Institute for Child Development and Education, the University of Amsterdam
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