[R-sig-ME] false positives?

[John Kingston]

I received the warning messages below in response to running the  
second model displayed below. The data file is attached to this message.

Warning messages:
1: In checkConv(attr(opt, "derivs"), opt$par, ctrl = control$checkConv,  :
   Model failed to converge with max|grad| = 0.212882 (tol = 1e-06)
2: In checkConv(attr(opt, "derivs"), opt$par, ctrl = control$checkConv,  :
   Model is nearly unidentifiable: very large eigenvalue
  - Rescale variables?

sfHIndR <- glmer(fRspRN ~ cStep +
	h1Context +
	h2Context +
	cQRT +
	(1 + cStep +
	h1Context +
	h2Context +
	cQRT | participant),
	family = "binomial",
	control = glmerControl(optCtrl = list(maxfun=1000000)),
	data = sfCompiled)

summary(sfHIndR)

# interactions with RT

sfHSxRtCxRtR <- glmer(fRspRN ~ cStep * cQRT +
	h1Context * cQRT +
	h2Context * cQRT +
	(1 + cStep +
	h1Context +
	h2Context +
	cQRT | participant),
	family = "binomial",
	control = glmerControl(optimizer = "bobyqa", optCtrl = list(maxfun=1000000)),
	data = sfCompiled)

The test suggested in a earlier post produced the output below. These  
values look small.

gg <- sfHSxRtCxRtR at optinfo$derivs$grad
hh <- sfHSxRtCxRtR at optinfo$derivs$Hessian
vv <- sqrt(diag(solve(hh/2)))
summary(abs(gg*vv))

#       Min.   1st Qu.    Median      Mean   3rd Qu.      Max.
# 6.720e-07 3.108e-05 8.866e-05 2.542e-04 1.745e-04 3.345e-03

Any advice about how to proceed? Thanks.
Best,
John



John Kingston
--------------------------------
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Linguistics Department
University of Massachusetts
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jkingston at linguist.umass.edu
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