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:
Validity refers to the similarity between the experiment value and the true value. For example, the weight of 1 mole of carbon should be 12g, but when we are measuring it could take different values depending on the instrument, person who is measuring, sample condition, external environmental conditions etc.