The actual validity of a proposed causal effect between a set of multiple independent variables on a dependent variable can be verified as empirically valid and true if the following evidence is present:
a. H1 can't be proven as valid, any lack of empirical evidence only supports the validity of Ho
b. finding from 2 other studies that obtain consistent correlation results with the 1st
c. a battery of measures that yield evidence of discriminate, convergent, & construct validity
d. multi-method, multi-trait measures showing evidence of time-series causal effects