Power Analysis for Structural Equation Modeling (Power Calculation)

Power calculation for Structural Equation Modeling with calculations based on the RMSEA index of fit, with options for charts of Power vs. Sample Size, vs. RMSEA, vs. Degrees of Freedom, and vs. Alpha Level

General

Element Name Description
Sample Size Sample size for the power calculation (acceptable range 2 to 150000).
RMSEA (R) Population RMSEA.

 A badness of fit coefficient; low values represent a good fit.

 (Acceptable range 0.00001 to 0.5).
Null RMSEA (R0) RMSEA specified under the null hypothesis.

 (Acceptable range 0.00001 to 0.5).
Degrees of Freedom (Df) Number of degrees of freedom for the chi-square statistic.

 (Acceptable range 1 to 5000).
Alpha Level Alpha level (Type I error rate for the overall significance test) (acceptable range 0.0001 to 0.25).
Hypothesis type Null hypothesis to be tested:

 One-tailed (R<=R0, a test of CLOSE FIT or R less than or equal to a reasonable value [e.g. 0.05] rather than an alternative value [e.g., 0.08] representing poorer fit);

 One-tailed (R>=R0, a test of POORER FIT or R greater than or equal to a proposed value.);

 One-tailed (R=0, traditional chi-square test of perfect fit.).
Detail of computed results reported Output level of detail selection:

 Power Calculation produces Power Calculation Spreadsheet;

 Pwr Calc plus Charts option produces, in addition, Power vs. Sample Size, vs. RMSEA (R), vs. Degrees of Freedom, and vs. Alpha Level charts.

Chart Parameters

Element Name Description
Number of Steps (For charts only). Number of individual steps for which to calculate power between the starting and ending parameter values for Power Charts (Min 4, Max 100).
Starting Sample Size (For charts only). Initial sample size for calculation of all Power vs. Sample Size charts.

 (Acceptable range 2 to 140,000).
Ending Sample Size (For charts only). Final sample size for calculation of all Power vs. Sample Size charts.

 (Acceptable range 5 to 150,000).
Starting RMSEA (R) (For charts only). Initial RMSEA value for calculation of Power vs. RMSEA chart (acceptable range -0.9999 to 0.9999).
Ending RMSEA (R) (For charts only). Final RMSEA value for calculation of Power Vs RMSEA chart (acceptable range -0.9999 to 0.9999).
Starting Degrees of Freedom (For charts only). Initial degrees of freedom for calculation of all Power vs. Degrees of Freedom charts.

 (Acceptable range 1 to 140,000).
Ending Degrees of Freedom (For charts only). Final degrees of freedom for calculation of all Power vs. Degrees of Freedom charts.

 (Acceptable range 2 to 150,000).
Starting Alpha Level (For charts only). Initial alpha level for calculation of Power vs. Alpha Level chart (acceptable range 0.0001 to 0.2499).
Ending Alpha Level (For charts only). Final alpha level for calculation of Power Vs Alpha Level chart (acceptable range 0.0002 to 0.25).