Draft excluders, part 1: what makes a good report?
By Rodger Munt, edited by Angela Lamacraft & Mike Lotinga, December 2017
Dr Rodger Munt FIOA is a retired scientist with 45 years of research experience. As a long-standing employee of the former Royal Aircraft Establishment, he led successive research teams where vetting of scientific reports for non-technical customers was routine. He regularly sees the reports issued to local authority planning departments in his capacity as a consultee.
This blog is an adaptation of an article published in the Nov-Dec 2015 Acoustics Bulletin, 40 (6), pp16-18.
Part 1: What makes a good report?
In writing any report it is important to take full account of the target readership in order to ensure that the conclusions are clear enough to allow the authorities to make correct decisions.
The following is my suggestion for a good report structure, some general advice on the issues of importance in conveying information to local authorities (LAs) and guidance for individuals undertaking technical appraisals.
Suggested outline of report
The report should contain the following:
A relevant title, unique report number, author and date;
A summary which can be understood by non-experts;
An introduction briefly explaining the background, basic issues, complications and approach adopted;
Technical sections describing the measurements, analysis, results and uncertainties;
Conclusions describing the impact of results and providing recommendations;
Appendices containing in-depth analysis of measurement and detail of prediction, backing up the other sections in the report, which can be scrutinised by other professionals. References to support the technical detail should either be easily accessible in the public domain or be provided with the report.
If measurements are made to a particular BS or ISO standard then all the required reporting items pertinent to that standard must be addressed either as an appendix or in the main body of the report. My preference is for the definitions and technical terms to be provided in an appendix as these can be a distraction if left in the main section of the report.
The summary, introduction and conclusion should be in a form which can be absorbed by authorities who, in many cases, may not have the expertise to fully understand the technical sections.
An acoustics report should contain a brief non-technical summary, written by a competent acoustician, providing simple points that can be understood by a non-specialist. It should explain exactly the new, existing or modified features of developments, how these are affecting the noise climate, the bearing on the local situation and what measures are to be implemented to mitigate the effects. All points within the Summary should be substantiated in full by way of detailed evidence provided elsewhere in the main report.
This should describe the reasons for needing an acoustic study and provide a description of the relevant noise sources. Any relevant background information, including any previous study, should be explained. The existing environment needs to be described and shown in plans of the area, including the topography between sources and sensitive receivers. A basic description of each piece of equipment generating noise is appropriate here along with general detail of its acoustic characteristics, including an indication of whether the characteristics are likely to pose problems and, if so, what solutions will be examined in the main body of the report. The specific details of the sources, e.g. tone levels and frequencies, should be left to the technical sections.
Main technical sections
These should contain detail of measurements and their analysis and any prediction method and assumptions. Reference to the various standards and the specifics of how they are applied, with diagrams of measurement locations, should be supplied. In all cases an assessment of uncertainty is needed for the sound levels predicted or measured.
Full disclosure of scientific method
The evidence underpinning all advice and reports should be robust and obtained using reproducible scientific methods which allow the reliability of data to be verified.
One of the main principles of the scientific method is the practice of full disclosure to allow someone else, working independently, to accurately replicate the scientific study or experiment. This enables careful scrutiny by other acousticians and professionals, giving them the opportunity to verify results and to analyse and interpret them independently (see the IOA Code of Conduct clause A1.4: Ensure that primary data used in any publication or report are available in a form that would allow for independent scrutiny and that sufficient details of any experiments, by which the data were derived, are available to allow others to replicate such experiments.)
Full disclosure of the underlying data used to support conclusions helps to reduce professional scepticism and is particularly important when uncertainty or scepticism is expressed by the public or third parties over the claims sometimes made in reports.
Some examples of technical issues I have encountered when reviewing reports/papers will be given in the 2nd part of this blog.