That arises from inaccurate sampling frame, data clarification or verification methods, reporting or coding of data, and/or specifications. It may also arise from poorly designed survey questionnaires, improper sample allocation and selection procedures, and/or errors in estimation methodology.
riff (rÉªf) n. 1. an ostinato melodic phrase accompanying a soloist in jazz or rock music. 2. any variation or improvisation, as on an idea. v.i. 3. to perform a riff. [1930â35; perhaps alter. of refrain 2] riff Past participle: riffed Gerund: riffing
A riffle is an area of fast moving, churning water. A run is an area of smoothly moving water. A pool is an area of stagnant water. Each habitat type supports different types of aquatic life, so a stream with a greater diversity of habitat types will generally support a greater diversity of organisms.