[R-sig-ME] p-value for fixed factor in lmer

[Henrik Singmann]

Alternatives to the options mentioned:

- function mixed() in package afex (disclaimer: I am the author of said package)

modelA <- mixed(percentV ~ tempo + (1|speaker) + (1|sentence),data=bt.data)

- anova(..., test = "F") in package car (author is John Fox):

modelA <- lmer(percentV ~ tempo + (1|speaker) + (1|sentence),data=bt.data)
anova(modelA, test = "F")

Both use KRmodcomp from pbkrtest to obtain p-values (which was mentioned by Tom Philippi) and should return the exact same values.

Benefit over pvals.fnc is that the random effects can include random slopes!

Cheers,
Henrik  


Am 16/05/2013 00:03, schrieb Volker Dellwo:
> Dear Mixed Model users,
>
> below is an lmer function for which I calculated p-values with pvals.fnc. In the output I receive five p-values for the fixed factor 'tempo', one for each level. What I would want, however, is a p-value for the entire factor which I can't manage....
>
> Many thanks for any suggestions!
>
> Best wishes,
> Volker
>
>
> MODEL:
>> modelA <- lmer(percentV ~ tempo + (1|speaker) + (1|sentence),data=bt.data)
>  > print(pvals.fnc(modelA))
>
> OUTPUT:
>
> $fixed
>              Estimate MCMCmean HPD95lower HPD95upper  pMCMC Pr(>|t|)
> (Intercept)  42.7346  42.7392    40.2256    45.1771 0.0001   0.0000
> tempo2       -0.1815  -0.1822    -1.0326     0.7087 0.6728   0.6737
> tempo3        0.7979   0.8023    -0.0953     1.6719 0.0768   0.0645
> tempo4        1.1526   1.1504     0.2812     2.0028 0.0088   0.0077
> tempo5        1.2742   1.2740     0.4183     2.1488 0.0042   0.0032
>
> $random
>      Groups        Name Std.Dev. MCMCmedian MCMCmean HPD95lower HPD95upper
> 1  speaker (Intercept)   3.4334     2.3338   2.3684     1.7773    3.0468
> 2 sentence (Intercept)   3.6911     2.5546   2.6462     1.6115    3.7921
> 3 Residual               3.1209     3.1974   3.2010     3.0061    3.4117
>

-- 
Dipl. Psych. Henrik Singmann
PhD Student
Albert-Ludwigs-Universität Freiburg, Germany
http://www.psychologie.uni-freiburg.de/Members/singmann