COLLADA viewers supporting transparency

Can anyone tell me if there are there any issues with COLLADA viewers supporting material transparency?
I am fairly new to COLLADA files, and am working on writing my own, but no matter what I do, change alpha channel values, toggle the <transparent opaque= > attribute, and the <transparency> tag, I can’t seem to see any difference in my output. My test file has a texture map with a pane of glass in front of it, but the glass looks opaque in the viewers. I am writing with COLLADA version 1.4.1, and am using the viewer that comes with the COLLADA DOM (although my app is not using COLLADA DOM), and have also been using the SwirlViewer from PineCoast. I see the same results in both, which is no transparency effects whatsoever. I even found random example dae files from the internet, which render fine, but show no difference when I manually change the effects’ transparency fields.
I’ve searched around and haven’t found much of a discussion about this. Is transparency an effect that is typically supported?
Any help or advice is greatly appreciated!