Power Analysis for Structural Equation Modeling (Sample Size Calculation)

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

General

Element Name Description
Power Goal Power Goal for the sample size calculation (acceptable range 0.65 to 0.9999).
RMSEA (R) Population RMSEA.

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

 (Acceptable range 0.0 to 0.5).
Null RMSEA (R0) RMSEA specified under the null hypothesis.

 (Acceptable range 0.0 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; choosing this option will set R0 to zero.).
Detail of computed results reported Output level of detail selection:

 Sample Size Calculation produces Sample Size Calculation Spreadsheet;

 Spl Size Calc plus Charts option produces, in addition, Sample Size vs. Power, 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 sample size between the starting and ending parameter values for Sample Size charts (Min 4, Max 100).
Starting Power (For charts only). Initial power value for calculation of Sample Size vs. Power chart.

 (Acceptable range 0.05 to 0.99).
Ending Power (For charts only). Final power value for calculation of Sample Size vs. Power chart.

 (Acceptable range 0.1 to 0.999).
Starting RMSEA (R) (For charts only). Initial RMSEA value for calculation of Sample Size vs. RMSEA chart (acceptable range -0.9999 to 0.9999).
Ending RMSEA (R) (For charts only). Final RMSEA value for calculation of Sample Size vs. RMSEA chart (acceptable range -0.9999 to 0.9999).
Starting Degrees of Freedom (For charts only). Initial degrees of freedom for calculation of Sample Size vs. Degrees of Freedom chart.

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

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