(a) The template includes a number of options for you to consider in improving your sampling efficiency:
(1) The base option.
(2) The APTL option.
(3) The PPMT option.
(4) The grouping option.
(b) You may use the base option if you are going to estimate both UPT and PMT (i.e., you will not be using 100% counts for either UPT or PMT), and
(c) Any of the other three options has the potential to improve your sampling efficiency over the base option:
(1) Sampling plans under the APTL option are based on how APTL in absolute terms varies across your service units.
(2) Sampling plans under the PPMT option are based on how APTL relative to average route length varies across your service units.
(3) Sampling plans under the grouping option are based on the idea that relevant statistical variation may be smaller across service units within sub-segments of your service than across all service units of your entire service.
(d) Additional options become available when service grouping is combined with each of the other three efficiency options.