I'm afraid that I will respond to your question with some questions of my own!
I think that where to start thinking is how you define the term "promote" and how that fits into the context of primary education and specific outcomes. In addition, you would need to know what "promotion" looks like, so that when you see it, you would recognise it. Also, you would need to define what you mean by "NGO", as well, so that your results would be clear.
One way to look at how they have supported education would be through the effect they have had on Primary Education. How would you test this? You can have two groups, essentially. One would be some select schools where there have been no NGO activity at all and the other would be schools that have had NGO activity (or promotion, in the way you had defined it). You would then need to fashion out parameters that explain how you intend to measure the effect of the NGO's on the outcomes you think are measurable. For example, you could look at individual or mean performance dis-aggregated for gender. Remember, you want to compare the effect of NGO activity as a proxy for promotion in primary education. The two groups I mentioned above would be your "Control group" (the group of schools that have had no NGO activity) and the "Experimental group" (the one that has had NGO activity).
This is basically a rough guide to understanding how promotion can be measured but please note that there are other more critical questions that you would need to answer in order to have a robust result that you have "confidence" in.