Early on in a pilot study, researchers discovered that it was impossible for assessors to consistently enumerate the total set of nuggets contained Let r # of vital nuggets returned in a response a # of okay nuggets returned in a response R # of vital nuggets in the answer key l # of non-whitespace characters in the entire answer string in a system response, given that they were usually extracted text fragments from documents (Voorhees, 2003).
a penalty for verbosity serves as a surrogate for precision.