The inspiration for the Symbolic Kinship Program was an earlier program developed by students of Hummel that gives numerical answers to such problems. The novelty of the Symbolic Kinship Program is that it produces explicit algebraic formulas. Naturally, once the formula is obtained a numeric answer can quickly and trivially be computed, so the formula is clearly as good as a number. In addition it provides many advantages, such as verifiability, insight, and modelling.
In principle the formula may be arbitrarily complicated and the time to derive it arbitrarily long depending on the complexity of the problem. However, the satisfying and lucky fact is that the formula complexity grows only slowly with the complexity of the problem. All practical problems that have arisen require only seconds on an ordinary desktop computer, and even more fanciful problems take only minutes.
Foundindumpster/Unfound : Mary + Joe Kimberley : Wife + Foundindumpster/Unfound |
Missing body analysis |
and symbolic genotype specifications such as | |
Foundindumpster pq Mary qr Kimberley q |
1 / (2q + 4qq)
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The prototype kinship program then offers to evaluate the expression for user-specified values of the gene frequencies i.e., if q=0.1, the likelihood ratio from this locus is 4.17 favoring the proposition that Foundindumpster, rather than some untyped and as yet Unfound body is the missing person.
After a while I added a mechanism that allows the user to accumulate the answers across several loci and save the work. The resultant product seemed a useful toy. It is included as part both of DNA·VIEW of the PATER package. But it is a stand-alone tool in the sense that it doesn't interact with any of the other mechanisms of either suite of programs.
Reconstruction report | ||||||||||||||||||||||||||||||||||
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D8S1179 | ||||||||||||||||||||||||||||||||||
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I did, though, include a separate facility that would prepare a layout of the available genetic data, as preparation for the user about to perform a Kinship analysis. Assuming the DNA types are available in DNA·VIEW, the "Reconstruction report" produces a tableau that shows a set of consistent symbolic genotypes for each person (such as pq, qr, q above), and the frequencies for each allele. That saves a bit of time for the analyst.
The incest example mentioned above is a more involved example of the use of the Kinship program.
The principal stroke was to feed genotype and frequency information directly to the kinship module. The user of the "Immigration program" or "Immigrator" is therefore freed from deciding the genotype patterns the program does that and indeed of any locus-by-locus interaction. An hour of analysis is reduced to a minute.
Of course that may do no good there is still Parkinson's law. But it surely does no harm.