I’m working with Alive & Thrive, a Gates Foundation funded project to improve young infant and child nutrition in a number of third world countries. Net-Map is part of the monitoring and evaluation component that is led by IFPRI. The question we are looking at at the moment is: If the project aims at changing the networks related to infant nutrition, how can we monitor if it actually does. And who do we need to ask to figure this out.
The initial intuitive approach is to ask those people who are knowledgeable about the issue and the existing networks now and ask them again towards the end of the project. But looking at it more closely I realized: One of the goals of the project is get groups and individuals involved who are not interested in the issue as of now. Sure, if you ask the experts now and in three years, they might say that these marginal actors have become more involved. But you would get a so much brighter picture if you ask the marginal actors now (when they have a rather fuzzy vision of the network and place themselves at the fringes) and after the intervention (when, hopefully, they know much more about how the network works and put themselves in a more defined position). So even though the before interviews with marginal actors will be confusing, not very efficient and lead to little reliable data about how the network works at the moment, you need exactly these unclear pictures from the beginning of the project to be able to show afterward that you did have an impact on their involvement and network knowledge. And if these interviews are additional to the core actor interviews, you will still get a pretty good picture of the before and after network as a whole.
In my typical “learn more about a network in short time” projects I would recommend only interviewing people who are knowledgeable about the network and stop the snowballing when the answers start getting boring (saturation point). But for monitoring and evaluation purposes I might have to re-think this recommendation. So my working recommendation now would be: Interview some overview experts / highly involved actors and interview those whose network position and network perception you want to change. Get a combined network picture for before and after from your highly involved actors. But also compare the individual before and after networks of your target population.