Identification by elimination

I apologize up front because I tried to search the topics to see if there was something similar to this but couldn’t find anything so if you redirect me to the appropriate threat, if it exists, that will be appreciated.

I am a herpetologist but I like to consider myself a jack-of-all-trades when it comes to my knowledge set on other organisms but of course this means that I often know enough to be dangerous but may still be lacking in certain areas. I try to continually improve my knowledge by doing identifications and it helps me become more familiar with the organisms I am trying to learn. However, it can be very cumbersome. Let me give an example.

Let’s say that I have taken a picture of a beetle and I want to find out what it is. My problem is that I know enough about beetles to know most of the major groups but maybe this particular beetle is something I am very unfamiliar with and so the sleuthing begins. Currently I have to search through the list of possible beetles to try and find something that comes close and then I look at the taxon to see if I can’t narrow it down. The beetles of Texas is a very long list to go through!

What if I could already narrow down the field of beetles by checking off groups that I know it doesn’t belong to. Maybe I don’t know exactly what it is but I know it isn’t a scarab, or a tiger beetle, or a dung beetle. I could dramatically reduce my search if I could eliminate those groups in the list of possibilities.

I mention this because this comes up a lot with moths. I know it isn’t a butterfly, a saturnid or a geometrid but that is all I have at the moment and yet my list of possibilities will still includes all of those. So at least a few times a day I am wishing I could not have to look at the organisms that I know that the observation is not.

I know there is an “exclusion” category in projects (which is wonderful) and I guess I would like to see an exclusion category when looking through organisms for observations. I think this would not only speed up the process but help me in my own education.

Perhaps there is a way of doing this that I am unaware of and so if this post only serves to highlight my own ignorance then that is okay as long as I find a better way to do identifications.

There is a “without_taxon_id” paraemter that you can add to search URLs, look for it on the page.

Downside is that you need to work out the taxon_id numbers for each taxon.

Thanks for directing me to the search page using URLs. While this is helpful it doesn’t really help with being more efficient. The downside you point out is a pretty big downside.

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I’m a tad puzzled (and at the same time somewhat intrigued!) by your question. This is how I identify something (if I’m not already very familar with what it is): I have been doing IDs for long enough now to have some idea what sort of characters are important in different groups. I know more about beetles than I do about plants, so I at least have some idea to what family any given beetle might belong. For plants I’m not quite there yet, but at least I know if it is a dicot, monocot, conifer, fern, etc. Then, if I can see characters which look like they might be important diagnostically, I try to put those characters into words in simple fashion and then do a Google image search for those characters in combination with the term “dicot” or whatever. I then scan the result for possible matches and if I see one, I do a quick search for that taxon in particular. After a quick review of the results, I make a judgement call on the strength of the match, and if it seems good to me (which may be a function of experience), I will suggest that as the ID. It seems that this method works quite well for me at least. I do make the occasional mistake, but not enough of them to be a real problem.

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@stephen_thorpe thanks for the feedback. I also do something similar to what you do. I first use what I do know to try and limit my search parameters and then look through my options. I will also expand those search parameters if that isn’t working. If that still doesn’t work then I will often do an image search in google or go to various places like to try and figure things out.

I think that part of my feature request is about being more efficient. I can only do this a couple of times in an afternoon when I have searched through 90 records on one species. It can also take a long time just because it may take awhile for all of the images to load when there is a long list of options.


I think the key point here is that I don’t often use iNat to ID stuff on iNat. Google picks up a lot of useful images from iNat anyway, and displays them more quickly and in a more convenient format. If I had to do it all on iNat itself, I probably wouldn’t bother anywhere near as often!


I’m going to close this as we’re not moving forward with this request.