For a majority of items, nonresponses and inconsistencies were eliminated by using the computer to assign entries and correct inconsistencies. In general, few assignments or corrections were required, although the amount varied by subject and by enumerator.
The assignment of an acceptable entry by machine was based on related information reported for the person or on information reported for a similar person in the immediate neighborhood. For example, in the assignment of age in the complete-count tabulations, the computer stored reported ages of persons by sex, color or race, household relationship, and marital status, each stored age was retained in the computer only until a succeeding person having the same characteristics and having age reported was processed through the computer; this stored age was assigned to the next person whose age was unknown and who otherwise had the same characteristics. This procedure insured that the distribution of ages assigned by the computer for persons of a given set of characteristics would correspond closely to the reported age distribution of such persons as obtained in the current census.
The extent of the allocations for nonresponse and inconsistency for most characteristics is shown for the United States in 1960 Census of Population, Volume I, Characteristics of the Population, Part 1, United States Summary, tables B-1, C-2, and D-1.
Specific tolerances were established for the number of computer allocations acceptable for a given area. If the number was beyond tolerance, the data were rejected and the original schedules were reexamined to determine the source of the error. Correction and reprocessing were undertaken as necessary and feasible.
The information on date of first marriage was transferred from the microfilmed stage II FOSDIC schedule to the computer tape without prior manual Editing. No manual coding was necessary because the information was precoded on the schedules. A computer edit was used to eliminate inconsistencies and to allocate blanks. There were three consistency checks. In the first check, the computer inspected the entries for each ever-married person to insure that the recorded date of first marriage was at least 14 years later than the person's date of birth and that it was not later than March 1960. All dates of marriage failing to meet this requirement were treated as if they were blank. The other two consistency checks related only to married couples. First, if each partner had been married only once, the dates of first marriage had to be the same. If they were not, the earlier of the two dates was changed to agree with the later one. Second, the date of first marriage for a spouse married more than once had to be earlier than the date of first marriage for a spouse married only once. If it was not, the date of first marriage for the person married more than once was treated as if it were blank.
The procedure for allocating date of first marriage when the person and his spouse had been married only once was to assign to the person the date of first marriage of the spouse. For the remaining allocations, three matrices were used. One matrix was used to allocate date of first marriage for married persons, spouse present, where one partner was married once and the other more than once, and where the spouse's date of first marriage was known. In this matrix the difference in years between the dates of first marriages of previously recorded spouses was stored in 10 cells according to the age of the husband. If the person was married more than once, his date of first marriage was obtained by subtracting this difference from the spouse's marriage date. If the person had been married only once, a date of marriage was obtained for him by adding this difference to the spouse's date of first marriage.
A second matrix, of six cells, was used to allocate the date of first marriage of ever-married women 14 to 44 years old with one or more children in the household. The difference between the number of years a previously recorded woman in this category had been married and the age of her oldest child was stored in this matrix according to the woman's own age. When a date of first marriage was missing, the last stored value was subtracted from the date of birth of the woman's oldest child to obtain, a date of first marriage to allocate. If the woman was married, husband present, and the date of the husband's first marriage was also unknown, and if both husband and wife had been married only once, the husband was assigned the same date.
A third matrix of 104 cells was used to allocate date of first marriage for all other persons. The number of years married was stored by age, sex, and whether married more than once. The last stored value was subtracted from 1960 to obtain a date to allocate for the person's year of first marriage. The quarter of the year in which the marriage occurred was then assigned by random allocation. If the person was a married woman whose husband's date of first marriage was also unknown, and if both, she and her husband had been married only once, her husband was assigned the same date.
It would have been possible under this system for the allocated date of first marriage to be inconsistent with the person's age or the date of the census, i.e., either less than 14 years later than the person's date of birth or later than March 1960. The principal means used to eliminate the first type of inconsistent allocation was to advance the date of first marriage beyond the date of the person's fourteenth birthday by the j amount that the date originally allocated was less than the date of the person's fourteenth birthday; where this yielded a date later than March 1960, a date of first marriage of January to March 1960 was assigned. The principal means used to eliminate the second type of inconsistent allocation was to subtract from January-March 1960 the amount by which the originally allocated date of first marriage was later than January-March 1960.
Despite the precautions taken to eliminate unacceptable dates of first marriage, a relatively small number remained after the edits described above. These were reallocated before tabulation of the data in the present report and those in report PC(2)-4E, Marital Status. Dates of first marriage were reallocated for about 316,000 persons, or three-tenths of one percent of all persons ever married. The persons with date of first marriage reallocated are included in the total number of persons with an allocated date of first marriage shown in tables A to D .and in appendix tables A-1 to A-3, and constitute about U.8 percent of that total. Because these reallocations were made after tabulation of data for reports PC(2)-3A, women by number of children ever born, and PC(2)-4A, Families, there are some minor differences between the statistics In those reports and the statistics in the present report and in PC(2)-4E, Marital Status.
The extent of allocation for nonresponse on date of first marriage is described in the section on "Quality of the Data," above. The figures shown there do not include the 0.2 percent of the population for whom data, were replicated because there were no sample data for them; for these persons, the characteristics shown are those for persons in the substitute households.