5.1 Ideally, interlaboratory testing of a method is conducted by a randomly chosen group of laboratories that typifies the kind of laboratory that is likely to use the method. In actuality, this ideal is only approximated by the laboratories that are available and willing to undertake the test work. The coordinator of the program must ensure that every participating laboratory has appropriate facilities and personnel and performs the method exactly as written. If this goal is achieved, the statistics developed during the ILS will be adequate for determining if the method is capable of producing satisfactory precision in actual use. If the program includes certified reference materials, the test data also provide information concerning the accuracy of the method. The statistics provide a general guide to the expected performance of the method.