Gifted Issues Discussion homepage Forums Identification, Testing & Assessment Mueller-Lyer Illusions... wt..?

My ds8 is supposed to take the Naglieri non verbal test next Monday. This week he came home with what he said was a practice packet for this (?) I was surprised they would do that, but also pleased to see he did really well with it. I think he ran out of time on the drawing part.
Anyway, yesterday he brought home another smaller packet which had similar things in it, some were a cross between an analogy and a pattern match so those were interesting.

I was puzzled by this, however:
A page entitled Mueller-Lyer Illusions.
Here is an example -
http://www.michaelbach.de/ot/sze_muelue/index.html

There were 3 questions on line length, and a couple on whether the white/negative part of a picture was visually more dominant than the black/positive part of the same picture.

Does anyone know if these optical illusion questions are part of the Naglieri or are they some sort of separate 'battery'?
What the heck are they trying to "TEST" for with these?

The main reason I was concerned what that on the first one the teacher said - oh yes, both lines are the same length, and then apparently she did some measuring and decided that in fact they were different.
DS was pretty confused/dismayed and - now that he's finally catching on to the fact that millimeter imperfections in worksheets are to be ignored - wants an explanation as to why all of a sudden people are paying attention to millimeter differences in length.

The negative-positive pictures were odd also, one just asked 'what do you see?'. I was wondering how that could be considered non-verbal...
There was one that had a bunch of cubes together like a tiled floor, and the question was do you see 7 or 8 cubes? I was like, well, why isn't 15 a possible answer?? Really my question is why would one answer be correct and the other not correct?
http://www.coolopticalillusions.com/optical_illusions_images_2/how_many_cubes_picture.htm


Any thoughts on this would be appreciated!

(Oh - also he is taking the SCAT today for jhu-cty and later next week he has Cogat, apparently - I didn't realize they would coincide this way, hope he doesn't get too sick of all this testing!!)

Well that makes a lot more sense, yeah, optical illusions just seem like trick questions!
But ds said it was the regular classroom teacher, so I am still not sure. I just told him not to worry about them if they do come up. Thanks for the reassurance!

Maybe the teacher is just trying to give an idea that there will be some different types of "questions" on the test, and if she gives some of these ahead of time, the ones on the test won't seem so odd? interesting....

Another thought - Maybe they are doing some sort of an LD or vision or "type of learner" screening too? I have absolutely no idea if optical illusions would be related to anything like this, but just throwing it out there.

I had fun with your links though! It brought back a memory of my first oral report. For some reason i picked optical illusions.