This blog post is part of a series on storing uncertain data in nodegoat: 'How to store uncertain data in nodegoat', 'Incomplete source material', 'Conflicting information', 'Ambiguous identities'.

You are often confronted with omissions or with inconclusive statements when you deal with historical source material. To let your dataset reflect the nature of your sources, it is important that you include these vague or uncertain statements in your data. This blog post will go over a number of strategies that will help you to deal with these cases in your nodegoat project.

A common scenario is a case where you lack information. When this happens, you can decide to leave a given description, date, or location empty. This gives you the ability to create a filter that finds the objects that have empty descriptions, dates, or locations.

In another situation you might encounter a source that is partially lacking. The source does provide you with some information, but is inconclusive about the certainty of the information. An example of this is the entry on John Chamberlayne in the Dictionary of National Biography:

Leslie Stephen, Dictionary of National Biography, v. 10 (Elder Smith & Co., 1887), page 9. Available at wikisource.

The first sentence of his entry reads: "CHAMBERLAYNE, JOHN (1666–1723), miscellaneous writer, a younger son of Edward Chamberlayne [q. v.], was born about 1666, probably in or near London."

We will discuss four strategies for accommodating this uncertain source: a true/false statement on certainty, a scale on the level of certainty, entering chronology statements, and entering geometries.[....]

The release of nodegoat 7.3 comes with a set of new features that have been developed in collaboration with various projects and institutes.

Repertorium Academicum Germanicum: Vague and Complex Dates

The Repertorium Academicum Germanicum (RAG) at the University of Bern has commissioned a major overhaul of the nodegoat dating functionality. With this development process, the core of nodegoat's date handling processes have been rewritten to account for date statements that are uncertain/cyclical/relational. These statements can be expressed using 'ChronoJSON' notation, to allow for a clean and understandable description of complex date statement. We used the EDTF format as a starting point for this development process, but had to conclude that this format was not equipped to make relational date statements or include custom periodisations (like 'Sommersemester').

With these new features nodegoat users can now make statements like 'letter X was sent two months after letter Y and two months before letter Z', or 'Person A graduated on one day two years before 1498 and two years after 1498'.

These features are completely integrated into all nodegoat's functionalities. This means that you can create complex filters that use relational or vague date statements, include these levels of vagueness in your visualisation, and make selections of data based on vague dates to perform network analytical calculations.[....]