APPENDIX. METHODOLOGY 



The following procedural notes describe the major technical meas- 

 ures that were utilized in the analysis of the demographic data on pp. 

 139-180, and summarize the procedure whereby samples were selected 

 from a number of Navaho rolls. 



SAMPLE SELECTION PROCEDURE 



The Navaho rolls from which sample data were obtamed consist of 

 ledgers in which are listed the names, sex, ages, household relation- 

 ships, location, and other information for each person on the roll. The 

 pertinent information for each enrolled person is listed on a single 

 line of the ledger; one ledger page typically contains 20 or 30 lines 

 with data for the same number of persons. 



In order to obtain an assured random sample of approximately 10 

 percent, I selected every 10th page of each ledger, starting from a 

 randomly selected number between 1 and 10. The age and sex of each 

 individual appearing on each sample page were recorded, startmg with 

 the head of the first family on that page. I.e., the age and sex of each 

 member of a household whose head appeared on the sample page were 

 recorded. According to this procedure, household members appearing 

 on a sample page whose head was listed on a preceding page were not 

 recorded in the sample. Conversely, household members appearing 

 on the succeeding page w^ere recorded in the sample if the head of the 

 household was listed on the sample page. 



The main advantage of this procedure over the more refined alter- 

 natives was its convenience in permitting an efficient clerical manipula- 

 tion of the ledgers. The purpose of these samples was to provide 

 representative age-sex distributions; no attempt was made to derive 

 precise estimates of the size of the total population from these samples. 



