[R-meta] Follow-up the coding question for meta-regression
Comments in-line
On 11/12/2023 23:21, ?????? via R-sig-meta-analysis wrote:
Dear Wolfgang,
Sorry for another interruption. I ran into two more questions. First,
when I was trying to write the code like this:
dat$duration <- cut(dat$duration, breaks=c(0,4,8,12),
labels=c(?NA?,?S?,?M?,?L?), right =FALSE)
and the system told me that ?x has to be numbers?, what should I do then?
(p.s. I am pretty sure that the part ?breaks? is also wrong?)
**Name of the moderator: duration
The distinction between the moderators:
NA = not provided
S (short) = 0-4 weeks
M (medium) = 4-8 weeks
L (long) = 8 weeks or above
So R is correct, that variable is not numeric but either character or factor. You would not need breaks either.
and my second question is that, here is one of the interaction I
performed:
[here I was trying to find out the interaction between the moderator
"instruction type" and "research design", and instruction type was coded
"ins" and with two categorical value "D (definition)" and "C(context)";
research design was coded "rede" and with two categorical value "D
(traditional)" and "O (others)"]
Model Results:
estimate se zval pval ci.lb ci.ub
intrcpt 0.9482 0.3581 2.6476 0.0081 0.2463 1.6501 **
insD 0.5142 0.4281 1.2012 0.2297 -0.3248 1.3532
redeO 0.4920 0.6163 0.7984 0.4246 -0.7158 1.6998
insD:redeO -1.2206 0.8256 -1.4784 0.1393 -2.8388 0.3976
Does the last line "insD:redeO" already means the interaction was not
significant with the p-value of 0.1393? Do I need to do the "anova(res.il,
btt3:4)" as suggested in the website?
Yes, that interaction is not adding anything important in your model. Michael
Nick ??? (Nick Chen) Email: t571 at wlgsh.tp.edu.tw <t5741 at wlgsh.tp.edu.tw> [[alternative HTML version deleted]]
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Michael