Hello all,
I'm testing for mediation using bootstrapping in AMOS. This method reports results for two-tailed significance, but my hypotheses are directional. With bootstrapping, significance is assessed based on confidence intervals - though a p-value is also provided. For regression, I would normally divide the p-value by two to get the one-tailed result. Would this be appropriate with tests of indirect effects too? In my case the two-tailed p value is .068 so it is potentially either marginal or significant depending on whether it is interpreted as two- or one-tailed.
Also, since, for these types of tests, CI rather than p-value is reported, is there an equivalent adjustment for the confidence intervals? I was told that I can calculate the confidence estimates using the estimate for the indirect effect +/- the std error times the value of the standard normal distribution corresponding to the desired Type I error rate (1.645 for a one-tailed test). However, when I do this, the CI I get is different from what AMOS produces. I can't tell if that is because I have misunderstood how to calculate the CI, or if it is because the AMOS numbers reflect bias correction that I am not accounting for when I calculate the CI myself.
Thanks in advance for any help you can give.
Akwasi
I'm testing for mediation using bootstrapping in AMOS. This method reports results for two-tailed significance, but my hypotheses are directional. With bootstrapping, significance is assessed based on confidence intervals - though a p-value is also provided. For regression, I would normally divide the p-value by two to get the one-tailed result. Would this be appropriate with tests of indirect effects too? In my case the two-tailed p value is .068 so it is potentially either marginal or significant depending on whether it is interpreted as two- or one-tailed.
Also, since, for these types of tests, CI rather than p-value is reported, is there an equivalent adjustment for the confidence intervals? I was told that I can calculate the confidence estimates using the estimate for the indirect effect +/- the std error times the value of the standard normal distribution corresponding to the desired Type I error rate (1.645 for a one-tailed test). However, when I do this, the CI I get is different from what AMOS produces. I can't tell if that is because I have misunderstood how to calculate the CI, or if it is because the AMOS numbers reflect bias correction that I am not accounting for when I calculate the CI myself.
Thanks in advance for any help you can give.
Akwasi