I don't think that anyone thinking of creating badges should think of a badge in isolation. I think of it like designing a basic label that I may want to tweak and edit to represent additional aspects. I went through this when I helped my husband design his canned fish labels--we needed something to show that each type (we have 14) came from the same business, but also had to include a way to differentiate species of salmon, whether it was smoked or plain--and then we added tuna and had scallops and oysters to integrate.If your design is too narrow at the outside--your badges may be radically different and not "sit" together as a suite or group.
That said, I think if you try to convey too much information, the image gets too visually complex and will not scale down well.
In any case, I do think that the badge is symbolic and must convey a message tied to what is being represented. The question is, what is the most important message to convey--for an institution granting a badge, the iconography of the institution might be of paramount importance and the skills/knowledge represented by the badge secondary. I think this is especially true where promotion of the institution is a key motivator. If a teacher/instructor is generating the badge--free of institutional guidelines and restrictions--s/he might focus solely on the content/skill learned.
Here's a curve ball--could there be audio badges? Where's the accessibilty in a strictly visual design?
Re. skills--I think some basic graphic design skills are necessary to find elements to represent the message of a badge. It's the equivalent of a visual tweet--but I think we've got less than 140 characters to do it in. There are plenty of free higher end graphics programs like www.pixlr.com to work with--or download GIMP or whatever turns your crank.
I'm almost eager to be on the opening forays into badging before my institution begins defining representational guidelines & requirements...think I have a bit more creative freedom. (Though I understand the importance of brand identity...sigh.) While our smaller educational institution has a department for this type of thing in Media & Public Relations--I think if everyone started using badges they'd be overwhelmed. I have to admit, too, that in desiging it myself I feel a sense of ownership and accomplishment.
It would give our Media & Art students something to do though....
I believe that promoting a university "brand" is important to educational institutions--it is a way to get the name out into the public. It's not just a badge, it's a badge from XXXX University. The popularity of a badge could generate interest--look at all the folks with a VIU badge!!! But if they are readily found, it might devalue the badge as well. Should there be a certain exclusivity of a badge??? Not sure. Think I would need to see what happens in some trials & do some focus groups re. response.