I’m not sure I’m doing this right, but it might influence my PhD… I have a feeling that somewhere along the way I should factor in the ‘new data should make your estimates more confident’ thing, but in a Fermi estimate we don’t take this into account, right?
A Fermi estimate of new data on Ophioglossum vulgatum bringing progress in true population estimates. (Problem: a plant with branching rhizome might give several stalks year—or might not give any, if a year is unfavourable—so you have to estimate the number of actual specimens from the number of stalks you see. Exposing and tracing the rhizome is (unethical—possibly lethal to the plant, but I doubt it if precautions are taken) the only way to know for certain. I think that if I dig up several patches of rhizomes, we can extrapolate on how many plants we have, and so have more accurate population censuses. It seems more useful if it does manage to lessen the gap between different researchers—another source of uncertainty—counting stalks.)
Let B, Annual benefit – more accurate estimates of population size (estimated number of clones/true n.o.c., measured in %)
Which would be useful to estimate the probability of population going extinct within 10 years of undisturbed succession (= final benefit).
Let B be about 20%, for a start. R(0) be current resources per year, around 6 man-days. Y/Z be around 4, if we take 4 years and count time already spent on research as an annual increment.
expected benefit ≈ 0.7 20% / (6man-days 1.4) = 1.6 %/man-day, so if I actually spend this season about 30 man-days on surveying populations, it would give me 50% closer-to-truth estimates of population sizes given censuses?
For 30 man-days, I need 30 populations to survey, and I only know about around 10. Suppose I want to estimate how closeness of stalks might reveal clonal structure below, and instead of digging plants up immediately, I count the stalks, see if there are any definable patches, and then try making three guess-models of clonal structures based on that observed patchiness.
How should it influence my Fermi estimate? If the expected utility of such severe actions is too low, I’ll just stick to counting stalks, and be content with less precize data.
Thank you.
There’s a continuum between Fermi estimates and more detailed models. At some resolution you’d definitely want to take into account the fact that new data will affect your confidence, but it may not be worth modelling at that resolution unless you think that this is one of the major routes to value.
With the scenario you outline, I think B is under-specified. You just say “more accurate estimates of population size”—in order to get this model to work you need some way of expressing how big a change in accuracy you’re looking at.
I’d also be wary of assuming that the only work that has occurred is the stuff you can directly count. Other scientists working on related problems might have produced a generalisable solution which would work here. To the extent that they haven’t, we should be more pessimistic about your chances of success than we would otherwise.
Thank you. By B=20% I mean that I will be 20% more certain of my estimate of the true number of single plants when I find a new population, count the stalks and roughly check how clustered they are, compared to ‘how confident I would be without this research’.
I will certainly look into works on other plants.
I think people just don’t bother. We don’t need to know exactly how many specimens are in a spot if we can say that mowing makes the environment more favourable to stalk production. We cannot really say much about genetic diversity and long-term conservation strategies, but considering that nobody is going to implement those strategies… It is, however, of some interest as to how such an ancient plant ‘games the system’ of the world we have—it is largely inbred, always must live with a fungus of some specificity, always ‘on the move’ (shrubbery incursion makes it die off, so it must produce spores before its window of opportunity is closed), glaciations have nudged it into retreats… and it still survives. It’s just an awesome little thing. *end of rant:)
I’m not sure I’m doing this right, but it might influence my PhD… I have a feeling that somewhere along the way I should factor in the ‘new data should make your estimates more confident’ thing, but in a Fermi estimate we don’t take this into account, right?
A Fermi estimate of new data on Ophioglossum vulgatum bringing progress in true population estimates. (Problem: a plant with branching rhizome might give several stalks year—or might not give any, if a year is unfavourable—so you have to estimate the number of actual specimens from the number of stalks you see. Exposing and tracing the rhizome is (unethical—possibly lethal to the plant, but I doubt it if precautions are taken) the only way to know for certain. I think that if I dig up several patches of rhizomes, we can extrapolate on how many plants we have, and so have more accurate population censuses. It seems more useful if it does manage to lessen the gap between different researchers—another source of uncertainty—counting stalks.)
Let B, Annual benefit – more accurate estimates of population size (estimated number of clones/true n.o.c., measured in %) Which would be useful to estimate the probability of population going extinct within 10 years of undisturbed succession (= final benefit).
Let B be about 20%, for a start. R(0) be current resources per year, around 6 man-days. Y/Z be around 4, if we take 4 years and count time already spent on research as an annual increment.
expected benefit ≈ 0.7 20% / (6man-days 1.4) = 1.6 %/man-day, so if I actually spend this season about 30 man-days on surveying populations, it would give me 50% closer-to-truth estimates of population sizes given censuses?
For 30 man-days, I need 30 populations to survey, and I only know about around 10. Suppose I want to estimate how closeness of stalks might reveal clonal structure below, and instead of digging plants up immediately, I count the stalks, see if there are any definable patches, and then try making three guess-models of clonal structures based on that observed patchiness.
How should it influence my Fermi estimate? If the expected utility of such severe actions is too low, I’ll just stick to counting stalks, and be content with less precize data. Thank you.
There’s a continuum between Fermi estimates and more detailed models. At some resolution you’d definitely want to take into account the fact that new data will affect your confidence, but it may not be worth modelling at that resolution unless you think that this is one of the major routes to value.
With the scenario you outline, I think B is under-specified. You just say “more accurate estimates of population size”—in order to get this model to work you need some way of expressing how big a change in accuracy you’re looking at.
I’d also be wary of assuming that the only work that has occurred is the stuff you can directly count. Other scientists working on related problems might have produced a generalisable solution which would work here. To the extent that they haven’t, we should be more pessimistic about your chances of success than we would otherwise.
Thank you. By B=20% I mean that I will be 20% more certain of my estimate of the true number of single plants when I find a new population, count the stalks and roughly check how clustered they are, compared to ‘how confident I would be without this research’. I will certainly look into works on other plants. I think people just don’t bother. We don’t need to know exactly how many specimens are in a spot if we can say that mowing makes the environment more favourable to stalk production. We cannot really say much about genetic diversity and long-term conservation strategies, but considering that nobody is going to implement those strategies… It is, however, of some interest as to how such an ancient plant ‘games the system’ of the world we have—it is largely inbred, always must live with a fungus of some specificity, always ‘on the move’ (shrubbery incursion makes it die off, so it must produce spores before its window of opportunity is closed), glaciations have nudged it into retreats… and it still survives. It’s just an awesome little thing. *end of rant:)