Table 2.

Descriptive Statistics on Predictor and Outcome Variables

Variable	M	SD	Range
Predictor variables
Age	64.92	8.10	50–79
Domain knowledge
PC knowledge	15.48	5.33	5–27
WWW knowledge	15.25	6.15	0–23
Crystallized intelligence
Shipley Vocabulary	35.46	3.80	17–40
MAB Information	26.25	6.90	11–37
WAIS Information	22.29	3.30	11–28
Fluid intelligence
Paper Folding (correct)	7.10	3.59	1–17
Letter Sets (correct)	16.52	5.92	2–27
Computation Span (simple span)	33.65	13.62	10–65
Alphabet Span (simple span)	39.42	9.68	20–65
Stroop Test (color–word score)	36.60	8.45	20–61
Trails (Trails B – Trails A)	69.13	129.27	5–961
Outcome variables
Rate of Correct e-mails (per hr)
Day 1	12.60	6.74	.48–28.01
Day 2	16.15	7.72	.73–32.89
Day 3	18.68	8.18	1.44–36.43
Day 4	20.18	8.33	4.18–39.17
E-mail processing time (min)
Day 1	2.76	1.04	1.36–6.00
Day 2	2.08	0.63	.91–4.48
Day 3	1.93	0.58	.91–3.85
Day 4	1.81	0.61	.96–4.25
Navigational efficiency
Day 1	1.10	0.54	.32–3.56
Day 2	0.86	0.43	.21–1.96
Day 3	0.67	0.39	.19–2.06
Day 4	0.58	0.35	.13–1.65

Note: SD = standard deviation; PC = personal computer; WWW = World Wide Web; MAB = Multidimensional Aptitude Battery; WAIS = Wechsler Adult Intelligence Scale.