Hi all! This is my first time posting to the forum. I am, admittedly, an
R novice (and statistical almost-novice) with little experience with mixed
models analysis. However, I was referred here by someone who is an R whiz,
if that counts for anything. Today I was attempting to use KRmodcomp and
got the following (rather confusing) output:
F-test with Kenward-Roger approximation; computing time: 2.10 sec.
large : Time ~ Grammar + Syllables + Order + (Grammar + Syllables + Order |
Subject)
small : Time ~ Syllables + Order + (Grammar + Syllables + Order | Subject)
stat ndf ddf F.scaling p.value
Ftest -25.141 1.000 39.975 1 1
Any idea what could be causing this? Here's the summary for ModelA, if
that helps:
Linear mixed model fit by REML ['lmerMod']
Formula: Time ~ Grammar + Syllables + Order + (Grammar + Syllables + Order
| Subject)
Data: data1
REML criterion at convergence: 317.5946
Random effects:
Groups Name Variance Std.Dev. Corr
Subject (Intercept) 0.021865 0.14787
Grammarspeed_slow 0.004639 0.06811 -0.78
Syllables 0.000408 0.02020 0.10 -0.69
OrderB 0.061705 0.24841 -0.58 0.66 -0.30
Residual 0.085452 0.29232
Number of obs: 571, groups: Subject, 41
Fixed effects:
Estimate Std. Error t value
(Intercept) 1.510485 0.122052 12.376
Grammarspeed_slow -0.123387 0.027608 -4.469
Syllables 0.033882 0.016742 2.024
OrderB -0.003791 0.064584 -0.059
Correlation of Fixed Effects:
(Intr) Grmmr_ Syllbl
Grmmrspd_sl 0.096
Syllables -0.923 -0.302
OrderB -0.209 0.152 -0.034
The t-value of -4.47 seems promising, so any help you could give me would
be greatly appreciated!
Again, I'm a novice. If there's any other information that you require
from me here, please don't hesitate to ask!
Thanks very much!
-Kevin
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