TABLE 3.

Models used, with measures of fit and terms included.

Model	Degrees of freedom		BIC		Log-likelihood		Model formula in lmer () notation
Linear	36		774.78		−291.31		log (value +1) ∼ factor (Dose)*Day
Unit	38		738.92		−268.05		log (value +1) ∼ factor (Dose)*Day + (1 | Incubator) + (1 | Incubator:ControlUnit)
Flusher	38		773.37		−285.27		log (value +1) ∼ factor (Dose)*Day + (1 | Incubator) + (1 | Operator:Day)
Both	39		736.87		−264.35		log (value +1) ∼ factor (Dose)*Day + (1 | Incubator) + (1 | Incubator:ControlUnit) + (1 | Operator:Day)
Full	40		721.97		−254.23		log (value +1) ∼ factor (Dose)*Day + (1 | Incubator) + (1 | Incubator:ControlUnit) + (1 | Incubator:TubeNo) + (1 | Operator:Day)
Term		Effect Type		Linear model		Unit		Operator	Both	Full	Comment
Dose*Day		Fixed		X		X		X	X	X	Equivalent to Dose + Day + Dose:Day
Incubator		Random				X		X	X	X
Incubator:ControlUnit		Random				X			X	X
Incubator:Circuit		Random								X	Accounts for repeated measures from the same circuit
Operator:Day		Random						X	X	X