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 rhythmic motif is the term designating a characteristic rhythmic formula, an abstraction drawn from the rhythmic values of a melody. A motif thematically associated with a person, place, or idea is called a leitmotif. Occasionally such a motif is a musical cryptogram of the name involved. A head-motif (German: Kopfmotiv) is a musical idea at the opening of a set of movements which serves to unite those movements.