New equipment has greatly increased both the speed and the accuracy of the phosphate spot test. It is recommended to take samples at 10 centimeter intervals in about one meter deep profiles as a routine method. The results must be interpreted in an ecological sense. Control samples can easily be misleading and should be replaced by P-sections in the area of interest. Study of the vertical distribution of phosphates can give information about the intensity of occupation, exclude modern influence, and give a rough age determination. It is therefore important to use the P-analysis three-dimensionally. See also AATA 18-1023, 19-162, and 20-32. -- AATA