Results

Linear Regression

Model Summary - wakefulness
Model	R	R²	Adjusted R²	RMSE
M₀	0.000	0.000	0.000	163.406
M₁	0.955	0.912	0.910	48.893
M₂	0.994	0.989	0.988	17.705

Note. M₁ includes hours.awake, ml.coffee
Note. M₂ includes hours.awake, ml.coffee, hours.awake:ml.coffee

ANOVA
Model		Sum of Squares	df	Mean Square	F	p
M₁	Regression	2.412×10⁺⁶	2	1.206×10⁺⁶	504.412	< .001
	Residual	231876.234	97	2390.477
	Total	2.643×10⁺⁶	99
M₂	Regression	2.613×10⁺⁶	3	871118.347	2779.123	< .001
	Residual	30091.281	96	313.451
	Total	2.643×10⁺⁶	99

Note. M₁ includes hours.awake, ml.coffee
Note. M₂ includes hours.awake, ml.coffee, hours.awake:ml.coffee
Note. The intercept model is omitted, as no meaningful information can be shown.

Coefficients
							Collinearity Statistics
Model		Unstandardized	Standard Error	Standardized	t	p	Tolerance	VIF
M₀	(Intercept)	353.775	16.341		21.650	< .001
M₁	(Intercept)	-194.227	18.475		-10.513	< .001
	hours.awake	23.458	0.968	0.730	24.229	< .001	0.997	1.003
	ml.coffee	1.224	0.056	0.658	21.838	< .001	0.997	1.003
M₂	(Intercept)	61.683	12.103		5.096	< .001
	hours.awake	-3.612	1.123	-0.112	-3.216	.002	0.097	10.292
	ml.coffee	0.266	0.043	0.143	6.197	< .001	0.223	4.477
	hours.awake ✻ ml.coffee	0.102	0.004	1.001	25.372	< .001	0.076	13.138

Influential Cases
Case Number	Std. Residual	wakefulness	Predicted Value	Residual	Cook's Distance
.	.	.	.	.	.

Note. No influential cases found.

Residuals vs. Predicted

Q-Q Plot Standardized Residuals

Classical Process Model

Model summary
	AIC	BIC	Log-likelihood	n	df
Model 1	4160.444	4186.496	-2070.222	100	0

R-squared
		R²
		Model 1
wakefulness		0.989

Path plots

Model 1

Conceptual path plot

Statistical path plot

Parameter estimates

Important : Parameter estimates can only be interpreted as causal effects if all confounding effects are accounted for and if the causal effect directions are correctly specified.

Model 1

Path coefficients
							95% Confidence Interval
			Estimate	Std. Error	z-value	p	Lower	Upper
hours.awake	→	wakefulness	23.013	0.344	66.911	< .001	22.339	23.687
ml.coffee	→	wakefulness	1.269	0.020	63.595	< .001	1.230	1.309
hours.awake:ml.coffee	→	wakefulness	0.102	0.004	25.895	< .001	0.095	0.110

Note. Moderation effect estimates are based on mean-centered variables.

Direct and indirect effects
								95% Confidence Interval
			ml.coffee	Estimate	Std. Error	z-value	p	Lower	Upper
hours.awake	→	wakefulness	16	13.650	0.511	26.695	< .001	12.648	14.652
hours.awake	→	wakefulness	50	23.635	0.344	68.791	< .001	22.961	24.308
hours.awake	→	wakefulness	84	32.714	0.496	65.990	< .001	31.742	33.685

Note. Moderation effect estimates are based on mean-centered variables.

Total effects
									95% Confidence Interval
				ml.coffee	Estimate	Std. Error	z-value	p	Lower	Upper
Total	hours.awake	→	wakefulness	16	13.650	0.511	26.695	< .001	12.648	14.652
	hours.awake	→	wakefulness	50	23.635	0.344	68.791	< .001	22.961	24.308
	hours.awake	→	wakefulness	84	32.714	0.496	65.990	< .001	31.742	33.685

Note. Moderation effect estimates are based on mean-centered variables.

Classical Process Model - Hayes

Model summary
	AIC	BIC	Log-likelihood	n	df
Model 1	4160.444	4186.496	-2070.222	100	0

R-squared
		R²
		Model 1
wakefulness		0.989

Path plots

Model 1

Conceptual path plot

Statistical path plot

Parameter estimates

Important : Parameter estimates can only be interpreted as causal effects if all confounding effects are accounted for and if the causal effect directions are correctly specified.

Model 1

Path coefficients
							95% Confidence Interval
			Estimate	Std. Error	z-value	p	Lower	Upper
hours.awake	→	wakefulness	23.013	0.344	66.911	< .001	22.339	23.687
ml.coffee	→	wakefulness	1.269	0.020	63.595	< .001	1.230	1.309
hours.awake:ml.coffee	→	wakefulness	0.102	0.004	25.895	< .001	0.095	0.110

Note. Moderation effect estimates are based on mean-centered variables.

Direct and indirect effects
								95% Confidence Interval
			ml.coffee	Estimate	Std. Error	z-value	p	Lower	Upper
hours.awake	→	wakefulness	16	13.650	0.511	26.695	< .001	12.648	14.652
hours.awake	→	wakefulness	50	23.635	0.344	68.791	< .001	22.961	24.308
hours.awake	→	wakefulness	84	32.714	0.496	65.990	< .001	31.742	33.685

Note. Moderation effect estimates are based on mean-centered variables.

Total effects
									95% Confidence Interval
				ml.coffee	Estimate	Std. Error	z-value	p	Lower	Upper
Total	hours.awake	→	wakefulness	16	13.650	0.511	26.695	< .001	12.648	14.652
	hours.awake	→	wakefulness	50	23.635	0.344	68.791	< .001	22.961	24.308
	hours.awake	→	wakefulness	84	32.714	0.496	65.990	< .001	31.742	33.685

Note. Moderation effect estimates are based on mean-centered variables.