[R-meta] how to interpreat a significant moderator variable but in-significant F test

[Martin Schwichow]

Hi,

My name is Martin Schwichow and I am a Juniorprofessor for physics education at
the University of Education Freiburg, Germany. Currently I am working on a meta-
analysis on studies that teach the concept of floating and sinking to students. I
am using the rma.mv function of the metaphor package.

Everything works fine but for two moderator analyses, I get strange result. The
omnibus F test is not significant but I have some significant moderator variables
(see below).The variables represent dummy coded variables representing different
levels of a factor. What does that mean and how can I interpret this results?
Best,
Martin

Input: rma.mv(g, se2, mods=~theo_inq+theo_con+theo_cop, random = lev, tdist=TRUE,
data=dat)

Output
Multivariate Meta-Analysis Model (k = 182; method: REML)

Variance Components:

            estim    sqrt  nlvls  fixed    factor
sigma^2.1   0.0569  0.2386    182     no  g_number
sigma^2.2   0.2529  0.5029     62     no  paper_id

Test for Residual Heterogeneity:
QE(df = 178) = 1423.5781, p-val < .0001

Test of Moderators (coefficients 2:4):
F(df1 = 3, df2 = 178) = 1.6910, p-val = 0.1706

Model Results:

          estimate      se     tval    pval    ci.lb    ci.ub
intrcpt     1.0847  0.1558   6.9624  <.0001   0.7773   1.3921  ***
theo_inq   -0.4419  0.2090  -2.1148  0.0358  -0.8543  -0.0296    *
theo_con   -0.2019  0.1887  -1.0697  0.2862  -0.5742   0.1705
theo_cop   -0.4507  0.3444  -1.3089  0.1922  -1.1303   0.2288

-- 
Jun.-Prof. Dr. Martin Schwichow
Pädagogische Hochschule Freiburg · University of Education Freiburg
Institut für Chemie, Physik, Technik und ihre Didaktiken
Kunzenweg 21 · D-79117 Freiburg
Tel: (+49) - (0)761 682 934

www.scientific-reasoning.com


	[[alternative HTML version deleted]]