From the NIAID website:
Significance and innovation are the peer review criteria reviewers use to assess the importance of your application, so you want to highlight these factors effectively.
Significance & innovation are explicit sections and should have a distinct category headings for the reviewers to identify. When I’m in study section and discussing a grant for which I am not responsible, I often go to these sections to give them a quick read. Make this easy for your reviewers to do. Here’s some info on significance. Innovation in another post.
Here are instructions for reviewers to help them evaluate Significance:
Does the project address an important problem or critical barrier to progress in the field?
If the aims of the project are achieved, how will scientific knowledge,technical capability, and/or clinical practice be improved?
How will successful completion of the aims change the concepts, methods, technologies, treatments, services, or preventative interventions that drive this field?
Again, make it easy for your reviewer to answer these questions. There should be a sentence in your grant (possibly even in the SA’s, but certainly in abstract) that reads something like “The significance of this project is that it addresses important problem#1″ or “If the aims of this project are achieved, the following wonderful things will be true….”
Some other advice from NIH to reviewers (you should read the whole thing):
Significance is evaluated and scored independently of the evaluation and scoring of Investigator(s), Innovation, Approach and Environment.
This is an overview of the 5 main criteria of evaluation for R-grants. K, T, F awards are a bit different from these.
The evaluation of significance assumes that the “aims of the project are achieved”
and/or will be “successfully completed.”
This is why you include a statement that says something about what will happen when you are done. It is often to better to word this as “when I finish” as opposed to “if I finish”.
Moreover, reviewers should evaluate the significance of the project within the
context of a (research) field(s). For example, autism is a significant field of study
but not all studies (projects) of autism are significant.
Research field(s) may vary widely, so it would be helpful if reviewers identify in
their reviews the research field(s) within which the project addresses an
important problem or critical barrier to progress.
Again, it is important to help the reviewer out here. This is part of defining the context in your Specific Aims. It is entirely ligit to say “The significance of this project lies its potential to change how diseases of bunny hopping are evaluated and treated“.
As long as that is true, of course.
Bottom line advice: know what the reviewers are looking for in terms of information and make it as easy as possible for them to find it.