OK. You have just implemented a new program (say a 9th grade transition program for incoming high school students) and you want to see if it was effective in achieving your goals. Sources of data could include:
a student survey/interview given at the end of the program to see what they liked, disliked, and learned
a parent survey/interview to see what they hoped their students would get out of the program
interviews/survey of faculty or other leaders of the program to get their impressions of the program's successes ad failures
a reflective ...
This response discusses some of the advantages and disadvantages of having multiple data sources when trying to evaluate the efficacy of a program.