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 type of fast drum beat characteristic of extreme heavy metal styles such as black metal, death metal and grindcore. Blastbeat is comprised at minimum of the bass drum and the snare drum, altough normally these two are accompanied by a cymbal such as hi-hat, ride, splash or crash.