SEM in R

Question 1

latent variable

Answer 1

=~

Question 2

regression

Answer 2

~

Question 3

(residual) variance

Answer 3

~~

Question 4

intercept

Answer 4

~ 1

Question 5

Fix all variances of latent variables to unity

Answer 5

fit <- cfa(HS.model,

data = HolzingerSwineford1939,

std.lv = TRUE)

Question 6

constraining parameter…

Answer 6

worsens model fit

Question 7

freeing parameter…

Answer 7

improves model fit

Question 8

fix loading multiple group

Answer 8

c(0.6, 0.8)*x3

Question 9

fix parameter in some, not all

Answer 9

c(a, b, NA, c)*x3

Question 10

weak invariance

Answer 10

group.equal = c(“loadings”))

Question 11

strong invariance

Answer 11

group.equal = c(“loadings”, “intercepts))

Question 12

strict invariance

Answer 12

group.equal = c(“loadings”, “intercepts”, “residuals”, “residual.covariances”))

Question 13

LGC manual

Answer 13

model2 <- ‘
int =~ 1bmi1 + 1bmi2 + 1bmi3 + 1bmi4 + 1bmi5
slp =~ 0bmi1 + 1bmi2 + 2bmi3 + 3bmi4 + 4bmi5 + 5bmi6
# Latent variances and covariances:
int ~~ int
slp ~~ slp
int ~~ slp
bmi1 ~~ bmi1
bmi2 ~~ bmi2
bmi3 ~~ bmi3
bmi4 ~~ bmi4
bmi5 ~~ bmi5
bmi6 ~~ bmi6
int ~ 1
slp ~ 1
bmi1 ~ 01
bmi2 ~ 01
bmi3 ~ 01
bmi4 ~ 01
bmi5 ~ 01
bmi6 ~ 01
‘

Question 14

orthogonal variance

Answer 14

x ~~ 0*y

Question 15

Fix variance

Answer 15

x ~~ 1*x

Question 16

fix loading

Answer 16

LV =~ ax1 + bx2

Question 17

unfix (marker approach)

Answer 17

LV =~ NA*x1

Question 18

constrain intercept

Answer 18

x ~ 0.5*1

mean structure = TRUE

Question 19

weak invariance manual

Answer 19

dem60 =~ l1y1 + l2y2 + l3y3 + l4y4
dem65 =~ l1y5 + l2y6 + l3y7 + l4y8
‘

Question 20

strong invariance manual

Answer 20

y1 ~ i11
y2 ~ i21
y3 ~ i31
y4 ~ i41
y5 ~ i11
y6 ~ i21
y7 ~ i31
y8 ~ i41
‘

Question 21

strict invariance manual

Answer 21

y1 ~~ res1y1
y2 ~~ res2y2
y3 ~~ res3y3
y4 ~~ res4y4
y5 ~~ res1y5
y6 ~~ res2y6
y7 ~~ res3y7
y8 ~~ res4y8

Question 22

equal latent variable variance, means latent variable

Answer 22

means, lv.variances,