The impact of a NITARP experience is difficult to quantify. We have anecdotal evidence that our program works. We are working on a formal evaluation of the 2013 class.
A summary of the high-level things we learned about the cumulative impact of NITARP can be found in the AAS poster entitled, "NITARP: Impact Assessment, 2005-2013", Rebull et al., from Jan 2014.
Tim Spuck collected information summarizing the impact of the Spitzer Space Telescope Research Program for Teachers and Students between 2005 and 2009 into one Impact Summary document.
Our website has many quotes from our participants about their time in the program.