I have been doing some research on the topic of "vocabularies of organization" (an interesting topic, I highly recommend diving into it.). As usual, I ran across some related material that fascinated me. There is something called The Jaccard Metric that helps analyze similarities between data sets. Dats sets can include computer code, statistics, or...you guessed it....words and vocabularies. So for example, if you have a text, you can measure other texts by how similar or disimilar they are in terms of vocabulary, and even concepts. The Jaccard Metric helps you discover the "distance" between the documents. That is, it helps you gauge, or grade the semantic, linguistic or conceptual distance between the standard text and other chosen texts.
Well, as I was thinking the other day about the APEST ministry matrix, I was struck by the lack of literature available for the apostolic and prophetic functions. Then as I thought about it some more, I realized that the further you move back from the Teaching ministry, the less material you can find. In other words, there is a plethora of material out there about the teaching/preaching ministry, but when you move backwards from the Teacher gifting to the Shepherd/Pastor gifting, there seems to be a bit less. It gets even less when you move back to the evangelism category, and then it gets even worse with the prophetic and the apostolic. The apostolic is by far the most bankrupt of all the gifts when it comes to literature and material to explain it, train people, and explore the conceptual and pragmatic issues surrounding that kind of entrepreneurial, pioneering ministry. I diagram it like this.