4 ms·

Also in genealogy: - estimated dates - calculated dates (e.g. someone was 30 in 1870, so he was born in "calculated 1840") - unreadable or unavailable months

Also in genealogy: - estimated dates - calculated dates (e.g. someone was 30 in 1870, so he was born in "calculated 1840") - unreadable or unavailable months or days (typically recorded as 1980-00-13) - time ranges with all of the above as boundaries e.g. "after 1760-03-00 and before calculated 1800" - plainly incorrect dates, but that's what the document says (1865-02-30) - no dates (some software tries to enforce putting in some data in for whatever reason) - dates with unknown calendar

Terr_ 6y ago
All plausible and scary. It sounds like a recipe for a system where the different qualities of dates are their own entity, and anybody doing a date-search needs to provide some criteria on the degree of specificity or certainty they require. For that matter, someone might want to do a text-based search on dates: "This damaged photo shows 196_-_1, which could be at least 20 different months..."
- isbvhodnvemrwvn 6y ago
  There's also another dimension to that uncertainty. Dates are typically attributes of events involving one or more people in various roles, and these events are (hopefully) attached to one or more sources. The type of sources you use affects the confidence of various attributes of the event (like dates or participants). In my area of research death records are typically a bad predictor for date and location of birth. When the records were managed by the churches (until after WWII pretty much), priests did not want to pester grieving family for the exact date of birth, so they relied on approximate age. Naturally the subject of the death record would not typically point out errors. On the other hand marriage records required looking at the actual birth records (sometimes mailed across the country), as these contained notes on all marriages of the individual (this was done to ensure monogamy). Is it on the genealogist to consider this confidence when specifying the date of the event, or should the software intervene? Due to complexity, the former is the industry standard. But maybe there are some brave (or stupid) people who will try to take it into account in the future.
  - jl6 6y ago
    I implemented a [private] genealogical data entry system based on the GenTech data model, which has a "surety scheme" entity, designed to capture perceived uncertainty. I also added a "Fuzzy Date", where every date-like value was decomposed into all its constituent components (year, month, day, hour, ...), all optional. It could also capture a range of such fuzzy dates, so it was possible to enter a "date" such as "The first of a month no earlier than 1950 and before June 1990". There was a loooong list of validation constraints to attempt to prevent contradictions being entered, and I think I caught all the cases, but...

Terr_ 6y ago

All plausible and scary. It sounds like a recipe for a system where the different qualities of dates are their own entity, and anybody doing a date-search needs to provide some criteria on the degree of specificity or certainty they require. For that matter, someone might want to do a text-based search on dates: "This damaged photo shows 196_-_1, which could be at least 20 different months..."

isbvhodnvemrwvn 6y ago
There's also another dimension to that uncertainty. Dates are typically attributes of events involving one or more people in various roles, and these events are (hopefully) attached to one or more sources. The type of sources you use affects the confidence of various attributes of the event (like dates or participants). In my area of research death records are typically a bad predictor for date and location of birth. When the records were managed by the churches (until after WWII pretty much), priests did not want to pester grieving family for the exact date of birth, so they relied on approximate age. Naturally the subject of the death record would not typically point out errors. On the other hand marriage records required looking at the actual birth records (sometimes mailed across the country), as these contained notes on all marriages of the individual (this was done to ensure monogamy). Is it on the genealogist to consider this confidence when specifying the date of the event, or should the software intervene? Due to complexity, the former is the industry standard. But maybe there are some brave (or stupid) people who will try to take it into account in the future.
- jl6 6y ago
  I implemented a [private] genealogical data entry system based on the GenTech data model, which has a "surety scheme" entity, designed to capture perceived uncertainty. I also added a "Fuzzy Date", where every date-like value was decomposed into all its constituent components (year, month, day, hour, ...), all optional. It could also capture a range of such fuzzy dates, so it was possible to enter a "date" such as "The first of a month no earlier than 1950 and before June 1990". There was a loooong list of validation constraints to attempt to prevent contradictions being entered, and I think I caught all the cases, but...