It is argued that P-values and the tests based upon them give
unsatisfactory results, especially in large samples. It is shown that,
in regression, when there are many candidate independent variables,
standard variable selection procedures can give very misleading results.
Also, by selecting a single model, they ignore model uncertainty and so
underestimate the uncertainty about quantities of interest. The Bayesian
approach to hypothesis testing, model selection, and accounting for model
uncertainty is presented. Implementing this is straightforward through
the use of the simple and accurate BIC approximation, and it can be done
using the output from standard software. Specific results are presented
for most of the types of model commonly used in sociology. It is shown
that this approach overcomes the difficulties with P-values and standard
model selection procedures based on them. It also allows easy comparison
of nonnested models, and permits the quantification of the evidence for a
null hypothesis of interest, such as a convergence theory or a hypothesis
about societal norms.
* University of Washington