I'd like to conclude with a few thoughts on teaching with geospatial information technologies, bringing Rogers' work (inappropriately) into an instructional context.
First, I think Rogers' five factors are worth considering from an instructional messaging standpoint. Whatever topic you're trying to teach (or present or advance, etc.), how compatible is it? How complex? Can people encounter just a little bit and understand it and then go further and understand it more deeply? (This is sort of like trialability; someone like Jerome Bruner might say it sounds like a spiral curriculum; someone like John Bransford might say this is a form of 'learning with understanding'.) Once someone understands the concept, is it relevant to their world or their work? (This is a form of relative advantage.) Are people able to act on the information? (This is a mangled application of observability.)
The more you can manage the complexity of your topic, the more relevance you can establish, the more you can make it mesh with pre-existing knowledge or beliefs (etc. etc.), the better the chance of your concept being understood and perhaps even spreading from person to person.
I think it's appropriate to indulge this line of thought because the concepts that geospatial tools let us observe and explore are frequently quite complex, perhaps INcompatible with existing knowledge or beliefs, or have a high threshold of prior required understanding (i.e., not very trialable). Consider the example of climate change: it's so very, very easy for people to think, "Gosh, it's snowing at the end of March...guess global warming isn't real!!!" Conversely, understanding the stock and flow relationships used in the climate change models is hard.
Fortunately, smart work with geospatial tools can help communicate these complex ideas more clearly / more simply: good map design, careful selection of data, sequencing of ideas -- perhaps our work with these tools will be the key to making more thorough understandings of our world accessible to all, and thus allowing vitally needed ideas (and policies!) to diffuse. Perhaps geospatial tools will help us be the change we want to see in the world.