Effect of sampling protocol and volunteer bias when sampling for macroinvertebrates

Effect of sampling protocol and volunteer bias when sampling for macroinvertebrates

We evaluated the efficacy of different field sampling approaches for volunteers sampling macroinvertebrates in low-gradient streams. We used a series of analytical metrics to compare results using the Environmental Protection Agency (EPA) multihabitat, the Minnesota Pollution Control Agency multihabitat, and EPA single-habitat sampling protocols. We also investigated the effect of 2 scenarios i...

Sampling bias and logistic models

In a regression model, the joint distribution for each finite sample of units is determined by a function px.y/ depending only on the list of covariate values xD .x.u1/,. . .,x.un// on the sampled units. No random sampling of units is involved. In biological work, random sampling is frequently unavoidable, in which case the joint distribution p.y,x/ depends on the sampling scheme. Regression mo...

Nutcracker, neurosis, or sampling bias?

Sampling Bias in BitTorrent Measurements

Real-world measurements play an important role in understanding the characteristics and in improving the operation of BitTorrent, which is currently a popular Internet application. Much like measuring the Internet, the complexity and scale of the BitTorrent network make a single, complete measurement impractical. While a large number of measurements have already employed diverse sampling techni...

Sampling Bias in Population Studies

Modiied versions of the life time distribution are often used in survival analysis. The modi-cations depend on how we choose individuals for the study and on the assumptions on the behavior of the population. A rigorous point process description of the Lexis diagram is used to make the sampling mechanisms and the preconditions transparent. The point process description gives a framework to hand...