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# Power Table for Effect Size d

Tabled entries are power to detect an effect size equal to the column of sample values. Table values represent the number of participants per condition (n) needed to obtain a significant result at the given alpha for the effect size and power level. This power table for effect size d was prepared using the program GPOWER. Tabled entries are power to detect an effect size equal to the column header with a sample whose size is the row header.

Two-Tailed α= .05 or One-Tailed α= .025
Power0.100.200.300.400.500.600.700.801.01.201.40
0.25332843822141086543
0.50769193864932221713975
0.6098124611062402821161186
2/3114428712873473324191297
0.701235310138785035262013107
0.751389348155885740292315118
0.801571393175996445332617129
0.85179745020111373513829191410
0.90210252623413285594434221612
0.952600651290163105735442371914
0.9936759204092311481037658382720
Two-Tailed α= .01 or One-Tailed α= .005
Power0.100.200.300.400.500.600.700.801.01.201.40
0.257251830.824731221713976
0.501329333149855539292215119
0.60160340218010266463427181310
2/3181045420311574523930201411
0.70192448221512279554132211512
0.75210852823613486604535231713
0.80233858625914895674938251814
0.852611654292165106745543282015
0.902978746332188120846248312217
0.9535648923982241441017457372620
0.994808120353630219413610077503526

In the above power table for effect size d, two-tailed and one-tailed alpha values are calculated for Two-Tailed α = .05, .01 or One-Tailed α= .025, .005.