I am all about data. I love to analyze, organize and synthesize information. When asked about how do I measure my effectiveness, I immediately think about the criteria in which my work is measured. Some would say the number of times I am requested for help. Some would say the ability for someone to use what we have worked on without me would be effective.
Without a standard criteria of what makes me effective, I'll create my own. I will measure my effectiveness in a few different ways. After a visit with a teacher, I will follow up with them to see how the work we did is going. If they are able to complete the work without any other assistance, I would consider that effective. If they have more questions because what we did has caused them to think deeper about the subject, I would also consider that effective.
We do collect data on the number of times that we are requested by teachers as well as the data we put in for those times where we aren't requested officially. I have not been very dutiful in putting those "other" times in my log. I have collaborated with my colleague to try a new strategy for documenting my time.
As we have been reassigned to campuses, I have made it a point to make it out to each campus for a visit with the Instructional Coaches, the librarian and the Principal, if they are available. That face time is crucial to improving collaboration. I have seen a few more teachers because I have been available on their campus. The most common saying is "Oh! I'm glad you're here! I had a question for you!"
Ultimately, there isn't one method that will measure effectiveness. It will be the overall picture of the data presented.