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Sampling |
Broadening
Participation in Biological Monitoring: |
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Choosing valid, appropriate, and effective sampling designs and methods—Although any participant can be included in the process of developing sampling designs and methods, creating ones that are feasible, efficient, statistically-valid, and trusted to produce credible data requires a great deal of specialized knowledge and experience. Valid and appropriate sampling designs and methods must match project goals, available resources, participant skills, logistical and practical considerations, quality standards, criteria for statistical rigor, and intended analyses. If data will be combined with other monitoring projects, development of standardized measures, common formats, comparable units, and uniform sampling protocols greatly facilitate the process. Some preliminary research into similar projects could provide ideas for addressing these issues. If the expertise to balance all these considerations is not available among the participants, then outside help should be acquired. This issue is so important that even the work of experts is improved by peer-review. For this reason, project coordinators might consider review of the sampling design and measurement protocols by technical panels, advisory groups, other specialists, or program managers. The Design module discusses the benefits of involving participants in all stages of project design, including technical aspects such as sampling. Although participants might not make decisions about complex sampling considerations, their insights can be valuable and their understanding of the choices provides them with confidence and ownership in the project. Participants can be involved in development of sampling design and data collection procedures in several ways: · If participants are unfamiliar with the concepts they could benefit from question and answer discussions or readings; · Some participants might be comfortable with phone conferences and email, while others might prefer one-on-one interactions or small focus groups where they can take sufficient time to clarify complex ideas and better engage in the process; · A site visit can engage participants in thinking about the project in the context of what they know about the local environment; · Specific questions can stimulate thinking about sampling. For example, if the participants are gatherers of a medicinal plant root, asking them if they know of areas where plots could be located could help avoid potential conflict between their traditional activities and data collection. Sampling protocols—We define sampling protocols as planned and systematic sets of methods and procedures for collecting data. Such protocols depend not only upon the chosen statistical design for sampling in a non-biased manner, but also the targeted organisms, field conditions, and other practical considerations. Protocols must match worker knowledge, skills, or training if they are to be effectively applied. Standardized protocols that are used consistently by all data collectors are integral to obtaining uniform data that can be validly compiled or compared. Examples include determining how and where to locate plots or orient transects, criteria for what to sample, precisely how to measure an attribute, or how to identify an organism. All aspects of how, what, where, and when to sample must be carefully considered, meticulously documented, and thoroughly taught if requisite consistency is to be achieved and maintained. Our references include several comprehensive manuals discussing these details for various organisms and for nontimber forest products. Deciding how to actually record the data depends on factors like equipment availability, the skills and training of field personnel, ease of checking for errors or making corrections, and anticipated weather conditions. Both manual and electronic data recording methods and procedures have advantages and disadvantages. Careful design of data forms or electronic data entry programs can reduce errors of omission by reminding the crew of information that needs to be collected. Following common systematic protocols, attention to detail, and double-checking for accuracy are essential components of quality control. Thorough training is necessary to implement the protocols consistently and properly. If data are not considered credible, then the efforts of the participants, and the resources expended, will be largely wasted, hence we address this critical issue separately in the following Quality module. Training, oversight, evaluation, and revisions—Many of the aforementioned considerations will be obvious to managers and employees who routinely engage in monitoring activities or field research, but additional attention to detail, oversight, and training might be necessary if participants conducting the field work are unfamiliar with why things are done the way they are instructed to do them. Careful oversight and immediate feedback are especially helpful at correcting mistakes and encouraging good habits when participants first start collecting data. Additionally, those who designed and documented the sampling protocols are unlikely to have anticipated all the exceptions and contingencies that will be encountered in the field. Knowledgeable supervisors who regularly accompany field crews in the early stages of sampling can quickly incorporate needed changes to the protocols. Once sampling methods and procedures are running smoothly, the project might wish to consider creating a training video for new personnel that join a field season already in progress. If field crews understand the goals of the project, the reasons for the sampling design, and why particular data collection methods are used, they will be more likely to make appropriate impromptu decisions when encountering unforeseen field or data collection circumstances.
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