To use WCF as WCF Rest service you have to enable webHttpBindings. It support HTTP GET and POST verbs by [WebGet] and [WebInvoke] attributes respectively. To enable other HTTP verbs you have to do some configuration in IIS to accept request of that particular verb on .svc files.
Concurrent validity is a measure of how well a particular test correlates with a previously validated measure. It is commonly used in social science, psychology and education. Don't miss these related articles:
In criteria-related validity, you check the performance of your operationalization against some criterion. How is this different from content validity? In content validity, the criteria are the construct definition itself -- it is a direct comparison. In criterion-related validity, we usually make a prediction about how the operationalization will perform based on our theory of the construct.