Thank you for writing to us with your question. In doing evaluations, it is of course important not to take more time than is necessary. But it is often more important to conduct an evaluation that gives an accurate portrayal of the effects of the initiative. An evaluation that is conducted too hastily can be misleading, and can sometimes be worse than no evaluation at all.
In your circumstances, it would be wise to first ask yourself these questions: (1) What specific evaluation questions do I want to answer? (These will often include questions proposed by the group you are working with.) (2) What action steps (or, what methods) will be necessary to answer these questions? And (3) How much time will it take to complete these action steps effectively? (Note here that you may also be able to enlist others to help you.)
When you have answered these questions thoughtfully and honestly in advance, that should help guide you in terms of what to do next. You may not be able to, or need to, conduct an evaluation that lasts for a year or more. But you may be able to, or need to, conduct an evaluation that takes more than a casual day or two.
There’s no one-size-fits-answer; the best answer instead depends on your starting questions. But having said that, evaluation is serious business; for the results of a serious and accurate evaluation can benefit a program or initiative very greatly, and is frequently well worth the time expended doing it.
You will also find many more detailed thoughts on how to conduct evaluations in the Community Tool Box, Chapters 33-36, and Toolkit 12.
We hope these thoughts may be helpful to you. Thank you again for writing, and all best wishes for success in your important work.