Search results for "Survey quality"
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The effect of random and density‐dependent variation in sampling efficiency on variance of abundance estimates from fishery surveys
2019
Abundance indices (AIs) provide information on population abundance and trends over time, while AI variance (AIV) provides information on reliability or quality of the AI. AIV is an important output from surveys and is commonly used in formal assessments of survey quality, in survey comparison studies, and in stock assessments. However, uncertainty in AIV estimates is poorly understood and studies on the precision and bias in survey AIV estimates are lacking. Typically, AIV estimates are “design based” and are derived from sampling theory under some aspect of randomized samples. Inference on population density in these cases can be confounded by unaccounted process errors such as those due …
How does the quality of surveys for nutrient intake adequacy assessment compare across Europe? A scoring system to rate the quality of data in such s…
2009
Research was conducted within the EURopean micronutrient RECommendations Aligned (EURRECA) Network of Excellence, to find the best practice in assessing nutrient intakes. Objectives include: to search for and use data on individual nutrient intake adequacy (NIA) assessment collected in twenty-eight European countries and the four European Free Trade Association countries; to design and test innovative tools for data quality analysis. The information was obtained using the method described by Blanquer et al. in the present issue. The best-practice criteria were devised to select the most appropriate survey in each country. Then a survey quality scoring system was developed in consultation wi…