It is!

Good. Satisfied that the tapes are less implausible than magic, she boxes them and the player up, labels the whole thing with her name and phone number, and drops it off at the professor's office the next time it's a weekend. Then it's back to researching experiment design and thinking about the preliminaries of a spell for identifying what kind of critter someone is.

The professor doesn't get back to her particularly soon.

As long as he's just busy and not, say, investigating the Case of the Impossible Tapes, that's fine by her. She has plenty of research-about-research to do, and a diagram to draw, specifically one for visual illusions using the "light" and "control" runes. The best way to implement the critter-detecting spell is probably to show people holograms of their true forms, both in terms of what the magic will understand and in terms of what potential critters will find useful, and the first step towards that is complex visual illusions.

This one is big from the start; she's going to be leaning on the magic for a lot of the data handling. Once it's done and checked, she puts a paperweight on it and recites her translation of, "A foot above this diagram, create a visual illusion of the object touching the diagram, to scale."

Doesn't do anything, doesn't expend the diagram.

Maybe she should attach the image to an object, like the glowing rocks. She lays out a hand mirror next to the paperweight and tries "Cause the mirror to show an image of the paperweight instead of what it would normally reflect." She expects that if this fails in any way other than silently, it will be optically bizzare.

It fails silently.

Mirror-scrying would be pretty cool, but might not be the easiest thing. What if she uses the same incantation she was using to burn diagrams into paper, but asks for an image of the paperweight instead of a diagram? It'll probably end up being the burnination version of black and white, but she can refine it from there.

Doesn't work!

Uninformative errors continue to be better than fatal ones, but they're still annoying. She makes another of the diagram she had been using to copy diagrams off artifacts, and tries to get the word "cupcakes" in twelve-point font.

That one fails.

Margaret refuses to believe a magic system that can do as much as runecasting can't take dictation. She gets more and more pedantic with her incantations until she discovers that it needs to be told to write in lowercase. That gets her "cupcakes" but not a species name.

And if she asks for "the name of the person touching the diagram" instead of "cupcakes"?

That it can't do.

Yup, sure looks like a data-gathering or data-handling type of problem. Can it do "the word 'cupcakes', if and only if the person touching the diagram is a dragon"? She had that failure a while ago when she accidentally referred to herself as a human in a different incantation, so it ought to at least be able to tell she's a critter and might be able to tell what kind.

Yes, it can do "cupcakes" under this constraint.

So far so good, but it might be working off her own knowledge, or only work for critters with medallions or something. She explains her latest project to her parents and asks to attempt the same test with them. While neither of them has any interest in getting a medallion of their own, they're both willing to have their potential checked in the name of science. 

This works too. Her mom is a dragon and her dad is a nondragon.

That's as she'd suspected. It's nice to be sure, and even better to know the spell works on its intended demographic. But right now it's only good for checking critter or noncritter unless someone already has a guess or wants to start going down a long list of types.

While she thinks about ways to get the magic to come up with species names on its own, she tries the test again on herself with "critter" (well, with the word French critters use for themselves on the internet) instead of "dragon". It never hurts to be sure, unless you count the hand cramps from tracing all these photocopies.

This works fine.

Hmmm, how to get it to come up with species names on its own. She tries writing "dragon", "sphinx", "pegasus", and "human", and "other" on bits of paper, writes some French, checks her email to see if the Arabic professor has anything to say to her, writes some more French, then lines up all the paper scraps on the diagram and tries:

"If the name of the species of the person touching the diagram is written on one of the pieces of paper in the diagram, make it glow; if not, make the piece of paper on which 'other' is written glow."

"Dragon" lights up.

Okay, so as a worst-case scenario she can have a setup with little plaques with the names of all the known critter species plus "human" and "other". She'd eventually want to make the whole thing an artifact that works whenever anybody touches a certain spot on it, both to save on diagrams and so she can add in a special case to make herself show up as a wyvern. But she's still holding out hope that she can find a way to get it to come up with species names itself, because any apparatus with the name of every species on it would be pretty large. Actually, how many known critter species are there, anyway? If she's ever looked it up she doesn't remember the answer.

There are several hundred, it transpires.

Could be worse, but still a huge pain to assemble. She clears away all but one of the paper scraps and tries "Write on this paper in twelve-point font the English name of the species of the person touching the diagram."

Nope!