Table 2.

Summary Statistics for ERP to Gain and Loss Trials

	Gain		Loss
Measurement	M (SD)	Range	M (SD)	Range
No. of trials
Baseline	29.36 (1.64)	18–30	29.32 (1.68)	19–30
Eight weeks	29.47 (1.51)	14–30	29.43 (1.51)	20–30
Data quality
SMEij
Baseline	1.53 (0.41)	0.73–3.95	1.48 (0.55)	0.66–8.05
Eight weeks	1.60 (0.46)	0.74–4.24	1.56 (0.47)	0.73–3.74
σij
Baseline	8.25 (2.14)	3.80–16.77	7.99 (2.69)	3.45–36.87
Eight weeks	8.65 (2.35)	3.91–22.83	8.44 (2.52)	3.99–20.48
Group-level internal consistency
	Estimate	95% CI	Estimate	95% CI
r xx
Baseline	0.95	—	0.93	—
Eight weeks	0.93	—	0.93	—
α
Baseline	0.94	(0.93, 0.95)	0.94	(0.93, 0.95)
Eight weeks	0.93	(0.92, 0.95)	0.93	(0.92, 0.95)
ϕk
Baseline	0.93	(0.92, 0.94)	0.93	(0.92, 0.94)
Eight weeks	0.93	(0.91, 0.94)	0.93	(0.91, 0.94)
ICC
Baseline	0.32	(0.28, 0.36)	0.30	(0.27, 0.34)
Eight weeks	0.28	(0.23, 0.32)	0.27	(0.23, 0.32)
Subject-level internal consistency
	M (SD)	Range	M (SD)	Range
ϕjk
Baseline	0.93 (0.02)	0.81–0.96	0.93 (0.03)	0.58–0.96
Eight weeks	0.92 (0.03)	0.77–0.97	0.92 (0.03)	0.79–0.97
ICC
Baseline	0.33 (0.06)	0.18–0.49	0.32 (0.06)	0.06–0.46
Eight weeks	0.30 (0.06)	0.10–0.48	0.30 (0.06)	0.11–0.48

Note: All estimates based on N = 276 at baseline and N = 187 at 8 weeks. SME_ij = standard measurement error; σ_ij = between-trial standard deviation; r_xx = odd–even reliability with Spearman–Brown Prophecy adjustment; α = Cronbach’s alpha; ϕ_k = group-level dependability; ϕ_jk = subject-level dependability.