I read the Param::Validate POD documentation The "problem" with this solution is that the validation process has to be called explicitely at the beginning of the method One solution would be the use of attributes. The attributes implementation could internally use the Param::Validate Advantages of such a solution: . integrated solution (no more explicit call to validation method) . consistent method "prototype" (constructor new and other methods use the same way for the parameters) What do you think about this proposal ? Gaetan