MARC: 100d
Author lifetime (MARC 100d)
MARC field [100$d] records the author’s lifetime (typically birth and death years) in free-text form. In the Fennica data, this field exhibits substantial heterogeneity in formatting, including approximate dates, alternative values, historical notations (e.g. BCE/CE), and non-standard textual descriptions.
To enable quantitative analysis, the field is processed through a multi-step cleaning and harmonization workflow. The procedure combines information from the original Fennica records and the Kanto authority data, prioritizing structured Kanto values where available. The harmonization includes:
- normalization of textual expressions (e.g. “noin”, “tai”, “kuollut”)
- resolution of alternative dates by selecting a consistent representative value
- conversion of historical notation (e.g. BCE/CE) into numeric form
- simplification of complex patterns (e.g. bracketed values, Extended Date/Time Format)
- removal of non-lifespan information (e.g. “toiminta-aika”, centuries such as “1700-luku”)
- standardization into numeric birth (
from) and death (till) years
The outcome is divided into two categories:
- Accepted entries: records where at least one valid year (birth or death) could be reliably extracted and represented numerically
- Discarded entries: records where the information could not be interpreted as a valid lifespan, or where ambiguity or format complexity prevented reliable extraction
In addition, a separate set of source conflicts is identified, where cleaned values derived from Fennica and Kanto disagree. These cases are retained for further inspection and potential feedback to the data providers.