What is a plausible explanation for this inconsistency?

Question

In the 1910 census, I have a family headed by Elias Riback (b. 1876), with wife Sophia (b. 1873) and children Annie (b. 1898), Harry (b. 1902), Bessie (b. 1904), David (b. 1906), and Bernard (b. 1908).

The 1920 census is consistent with this:

In the 1930 census, I find Ellis Ribeck (b. 1875), with wife Sophia (b. 1873), and children David (b., 1907) and Bernhardt (b. 1909). This is reasonably consistent.

In the 1910 census, the couple is reported to have been married for 13 years, placing the date of marriage in 1897, the year before the birth of the first child. Sophia is also listed as having five children, all living, which accounts for the entire family in 1910. So far, so good. In the 1930 census, however, Ellis's age at first marriage is listed at 22 (marriage date: 1899), while Sophia's is given at 33 (marriage date: 1906). While the families match on all other points, I am at a loss as to how to explain the discrepancy.

I also don't know who reported these numbers to the census taker. How is that information recorded in the 1930 census (if at all)? Finally, there is a notation "al" between the names of the two sons (David and Bernhardt). What does that mean?

Answer 1

Possibly the marriage question was misunderstood in 1930 and the number of years they have been married was entered for Sophia (that would fit). Doesn't explain the 22 for Ellis though.

The "al" after Bernhardt is actually "ab" (see another example further up the page).

Ab or ab—Indicates a temporary absence at the time of the census. This means the person lived at the residence, but was not present at the time the census was taken. This abbreviation is usually found following the name or relationship.

Source: Ancestry: What do the abbreviations in the 1930 census mean?

Answer 2

The 1930 U.S. census, "Instructions to Enumerators ...," is available online from www.census.gov. The University of Minnesota has also what appears an online transcription, "1930 Census: Enumerator Instructions."

I do not know what the notation "al" would mean; I do not recall working with that notation before.

As to the apparent inconsistent reporting about their ages at first marriage in 1930, the information does seem oddly out of place. The ages of the sons seem notably consistent; ages of the parents is almost so.

Interesting to me, is that on my first pass through the instructions, I did not find guidance about "who" should be asked (when to inquire of a child or a neighbor). From the U of Minn. transcription, the instructions do suggest a little caution on the inquiry for first marriage, "Where the marriage is evidently a first marriage, it may be good policy to ask for "age at marriage," rather than "age at first marriage," or to ask the question in this form and then make certain that the parties have not been married before."

Assuming you have other information about Elias/Ellis and Sophia, then the thirty years after-the-fact notion in that later census that his first marriage is given later (not earlier) suggests to me it is likely an error/oversight. Unless you have reason to believe that Elias/Ellis was married to two different women named "Sophia," then her record likewise seems likely an error/oversight.