Allow users to record absence data


One thing which would be really nice is to see where a taxon has been searched for but not found. I haven’t tried it, but I’m betting it won’t work like this as things are, but what we need is to be able to put a 0 (zero) into the observation field ‘count’ and have that observation shown on the taxon map as a peg of different colour to that of a >0 count. So, effectively, for any given taxon, the map would show presence, absence and unknown. This could be very useful for many purposes.


So a way to indicate effort and have presence/absence data?


One way of getting at how much effort went into looking without finding is looking at how many observations of similar taxa have been recorded in the area. For example, if thousands of bird observations have been uploaded in a park, but the bird I’m interested in has not been observed, that tells me something different than if almost no bird observations were taken there. I would guess that relatively few people posting data on iNat are searching for one species and nothing else.

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Not quite sure exactly what you are asking, but something like that is what I am suggesting yes. To be useful, it doesn’t need much in the way of effort indication though. An absence obs would always be trumped by a conflicting presence obs. What it means though is that I could go from place to place in an area, giving more or less the same amount of effort at each place, and so a null result would be informative in many cases, and it would be nice to keep track on the maps of where still hasn’t been checked at all.

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Yes, but that isn’t a feature that can be easily implemented! We should keep the “effort” issue a bit separate.

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Yes. This could show that an absence of observations is most likely due to an organism not being present as opposed to no iNatters around at the right time. This would make iNat data more complete and make range changes much more obvious.
One concern might be users that are less familiar with the species they’re looking for. Also, there might need to be a way to combine observations within a certain time frame. Especially with plants, you may not need 10 people on the same hike to record not seeing the same thing.

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Please give a look. It was designed to enable recording presence/absence data

Observations of absence vs presence

Is there a way to generate maps from the data?

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yep, just grab the lat/lons rendered here[taxon_id]=36204 or in JSON format[taxon_id]=36204 and plug them into your favorite mapping software

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I meant map them on iNat (=my favourite mapping software!)

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oh, has this been developed further? I feel like it was less fleshed out last time I tried it. Definitely worth trying out again at some point, maybe for things like inventory of plants in a natural community or a discrete wetland. itw ould be neat to get that functionality into the app someday… kind of like exercise apps, you can start the trip and then stop it when you are done. Though for plants, I don’t think I’d want to do it with the implication of absense (rather than not observed). In Vermont at least, and probably elsewhere too, there isn’t really any time of year you can literally identify every plant species because the spring ephemerals are gone by the time the fall asters are identifiable, etc…

Very neat though. Is it a depreciated part of the site or will it be actively maintained @loarie ?


The absence of a species at a time when it’s expected would be helpful in tracking how climate change is affecting flora and fauna.


Probably not that helpful (too many potential confounding factors). It may be more helpful for getting climate change funding, though! :)


@stephen_thorpe if you want to keep this request open, would you mind changing the subject to an action verb?


looks like trips might not work well with (auto-)obscured observations, which i suppose is good and bad

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@tiwane I didn’t open the request! Someone else split it off from another thread in which it was considered to be “off-topic”!


The simplest solution is the best. We have an observation field ‘count’. There is no reason not to enter 0 into that field, except that we don’t want the obs to show on the map in the same form as a >0 count.


Ah OK. Will I’ll change the subject.


I would have liked something like this earlier this year. I went to check on these/see them again a year later, and there was no sign of them, at all, which seemed very odd, as the second visit was only ten days later in the season.


well, if you’re going to use observation fields for now, i think i like some of the other ways people are handing absence data a little better. see