I'm with Elizabeth Shown Mills who says in her influential Evidence Explained: "As careful researchers, we cannot apply an easy, generic label—reliable or unreliable—to any document, much less any type of document."
This matters because Help:Sources & Help:Sources Style Guide say that WT's preferred style & format are based on Evidence Explained (EE) & associated Chicago Manual of Style.
The biggest problem with binary reliable-unreliable listing is that this has inherently pejorative connotations that go against the grain of careful research and researchers.
It would be much better for WT to seriously espouse EE in terms of language and the basic principle that, according to the EE's Evidence Analysis Process Map: "SOURCES provide INFORMATION from which we select EVIDENCE for ANALYSIS. A sound CONCLUSION may then be considered "PROOF" ."^
Application by WT of this EE basic principle could surely help avoid ludicrous treatment in Help:Uncertain to the effect that the following four items should be included among the list of original source examples:
- Books that cite primary sources. This would Include books that transcribe birth/marriage/death records as well as authored family histories or trees that cite birth/marriage/death records.
- History books that would have collected information from the subjects themselves.
- Newspaper articles with the publication name, date, and location.
- A proof summary of multiple sources of supporting evidence used to draw a reasonable conclusion.
The first three above items are by definition derivative sources; that is,.anything that is not an original source is a derivative source. The last item is a proof summary and not an original source.
In terms of Help:Uncertain's derivative examples, the list is evidently too restrictive; indeed, everything ever published that are not original sources, including the Internet, are derivative sources.
Inclusion of 'Family bibles with birth/marriage/death dates' as original source example is partly true and partly false. A bible is by definition a derivative source; the writeup of BMD / NDP data is evidently an original source. However, accordance to EE Process Map parlance, the bible is secondary information; the writeup is also secondary information, unless the author was present at all the BMD events written up in bible.
In summary, the short answer to the above G2G question, Is your source for pre-1700 genealogy reliable enough to use on WikiTree?, is that the current binary reliable-unreliable listing adopted for various projects is not coherent because it does not rigorously adhere to EE's rational, systems approach to history & genealogy research.
^ Refer for example to Using the Genealogical Proof Standard in Your Research.
Edit: From 'derivative example' to 'derivative examples'.