n_audio = length(levels(tlx$audio))
par(mfrow = c(1,n_audio))
for (i in levels(tlx$audio)) {
	boxplot(tlx_overall~guidance, outline=FALSE, data=subset(tlx,audio==i),
		main = "All Data", xlab = i, ylab="TLX (Overall)",
		cex =1, cex.lab = 1, cex.main=1, cex.axis=1, pch = 23,
		col = 3, lwd=.5)
}
dev.copy2pdf(device = quartz, file = "tlx_per_audio_x_guidance.pdf")
dev.off ();