I've got an svg file with many object across a canvas.

I'd like to select a group of objects that are contained within a rectangular area of this canvas.

I've followed the directions for a "rubberband selection" in this document:
http://en.flossmanuals.net/inkscape/too ... lect-tool/

However, when I release the mouse button, nothing is selected.

Is is possible to make a selection based on an area? If so, how do I do it?

I'd check the status bar... might be all objects are in a group, could be all are in a locked layer...

If you can upload (or link to) the file or a similar one, we can take a better look.

Maybe somewhat off-topic, but related to easily selecting/deselecting: are there other inkscape users interested in the feature request "rubber band/drag DEselect objects"? If so, maybe clicking the "Does this bug affect you" link above the description might help attract attention? And/or commenting it?

I find it to be one of those features that most programs have and that are sorely missing in Inkscape. Which remains one of my all-time favorite open source programs, I just love it. Developers are doing a great job.

Try clicking once on 1 of the objects, then look at the status bar. If it says "Group of...." then you can do Object menu > Ungroup (or use the button on the command bar, or key shortcut).

If you can't select even by clicking on 1 of the objects, then likely the layer is locked. Open Layers menu > Layers. Since I don't know anything about that file, I'm not sure how many layers might be there. But if you see any layers where the lock icon is a closed lock, that's probably why you can't select. Click once on the lock icon. First, you'll notice it becomes an open lock, and 2nd, you should be able to select on the canvas.

Or sometimes objects can be locked.

If neither of the first 2 steps works, can you share the file with us? You can attach from the full editor.