types and sources of interest, obtaining and/or developing the necessary input  data, and  running the appropriate models and/or methodologies.  Step 4: Coordination/Review and Documentation of Results  – Once the air quality  assessment has been conducted, the purpose of this step is to coordinate and review the  analysis with the appropriate agency and to address any comments  prior to moving  forward with the project/action. Upon completing the coordination/review process, the  final step is to properly document the results. As described  in  Section 4.1.4  (Step 4:  Document the Results),  this work entails reporting the assessment findings in narrative  and other formats that are appropriate, informative and easy to understand to reviewing agencies and the general public.  Within these four basic steps of the  air quality assessment process, there are a number of sub - steps or activities that are typically necessary. The remainder of this  Handbook  section describes  the sub-steps to each of the four basic steps.  Aviation Emissions and Air Quality Handbook  19$_{ }$