While the overall wording and content will no doubt need to be tweaked, particularly the very last paragraph where I am talking outside my knowledge, here is a suggestion that people can vote for or against and can make specific suggestions about:
Suggested guideline on Confidence in parent-child relationships:
Speculative is the lowest and default confidence level and should be used when the parent-child relationship does not meet the guidelines for a higher confidence level. In general this is the appropriate confidence level whenever there is no known primary source origin for the relationship. For example, a family tree posted on the internet without sources should, in most cases, be treated as speculative.
Documented, as a level of confidence, means simply that the information originates in a primary source. This is not an evaluation of the quality or acuracy of the specific primary source(s). A parent-child relationship should be set as documented when:
1. The information comes from a relative who is a 1st or 2nd degree relative to either the asserted parent or child.
2. The information comes from a person who personally met and knows the individuals as parent and child. (for example, a god-parent, teacher, or the next door neighbour etc.);
3. The information comes from a primary source document. Examples: birth or baptismal certificate, records in a family bible, wedding license, death registration, will, obituary, personal correspondence/memoires of the individuals listed in 1 and 2 above, a passport application, a census record that specifically gives relationships of the inhabitants of a household, etc.;
4. A source citing/derived from one of the above, such as a published genealogy that gives sources (i.e. the fact does or is claimed to originate in a primary source). Ideally the cited sources should also be independently examined.
Genetically linked should be used when DNA evidence supports a speculated parent-child relationship, but the relationship does not satisfy the requirements of being documented as given above. While there are cicumstances where DNA tests can produce false positives, or support more than one relationship, this is still considered a higher confidence than being documented only..
Confirmed should only be used when:
1. DNA evidence corroborates documentary evidence of a parent-child relationship. While this could still theoretically contain errors, this represents the highest possible confidence; or,
2. Where advanced DNA tests or analysis methods, such as Whole Gene Sequencing (WGS) or (triangulation?) have 'proven' a speculated parent-child relationship.