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
Riff Raff (rapper), from Texas. Riff Raff (band), a UK progressive rock band. Riff Raff, a band formed by Billy Bragg. Riff Raff (Argentine magazine), heavy metal magazine from Argentina. Riff Raff (British magazine), a London-based monthly rock magazine. Riff Raff (album), by Dave Edmunds.