Table 8.

Literature Comprising Meta-Analysis for the Power Law of Practice Exponent Parameter Estimation

Study	n	Mean age	Ages sampled	Power law constant	SE
Bherer, Kramer, Peterson, Colcombe, Erickson, & Becic (2005)	36	70	62–77	0.48	0.07
Charness & Campbell (squaring task, 1988)	16	67	59–75	0.43	0.11
Fisk, Cooper, Hertzog, Anderson-Garlach & Lee (1995)	104	72	65–81	0.55	0.09
Glass et al. (2000)	10	65	60–70	0.42	0.07
Hertzog, Cooper, & Fisk (1996)	104	72	65–81	0.48	0.1
Hoyer, Cerella, & Onyper (2003)	28	72	60–75	0.45	0.14
Jamieson & Rogers (2000)	40	69	60–80	0.45	0.12
Jenkins, Myerson, Joerding, & Hale (2000)	16	71	62–77	0.56	0.14
Ratcliff, Thapar, & McKoon (2004)	41	70	60–75	0.51	0.11
Rodrigue, Kennedy, & Raz (2005)	7	70	62–82	0.46	0.11
Strayer & Kramer (1994)	20	68	65–75	0.42	0.13
Touron & Hertzog (2004)	40	67	60–75	0.43	0.09
Touron, Hoyer, & Cerella (2001)	24	71	64–75	0.46	0.08
Welford (1958)	12	70	65–75	0.45	0.09
Weighted mean parameter estimate	498	70	59–82	0.49	0.39–0.59*

Note. n = number of participants in age range of interest per study.

^*Values represent plus or minus two standard deviations of means.