Along with relevance and focus the other crucial component of a good proposal is the methodology. A strong methodology, i.e. a feasible and coherent plan for how the investigation will be undertaken, is absolutely essential as it illustrates that the journalist has grappled with the topic and is likely to make a meaningful media impact with the investigation.
Interviews are usually a large component of methodologies, but is not sufficient to simply state that a journalist will go to a certain place and conduct interviews. A detailed and structured investigation should ideally include specific people already identified for interviews, the type of interviews to be conducted and the questions and topics that will be addressed to them, and an outline for how the interviews will form part of the investigation.
In addition, a methodology should include specific places/regions/areas/sites that the journalist intends to visit and what they intend to do there. A methodology will also be strengthened immeasurably by an outline of other strands of investigation that will be pursued in addition to interviews, e.g. court records, archives, site visits, data analysis and (in rare cases) undercover work.
For the ACRP, a good proposal is one with a relevant topic adequately focused, and clearly and concisely laid out with sufficient supportive information, along with a detailed and coherent methodology.