anchor.diff:                          if title.Contains word then acc + weight else acc) 0.
                   score
   
  +    let ``matching voltage`` : FeatureLearner = 
  +        fun sample ->
  +            fun obs -> 
  +                match (findMeasure pVolts obs.SearchTerm) with
  +                | None -> 0.
  +                | Some(v) ->
  +                    match (findMeasure pVolts obs.Product.Title) with
  +                    | None -> -1.0
  +                    | Some(r) -> closeness 0.5 v r
  +
  +    let ``matching wattage`` : FeatureLearner = 
  +        fun sample ->
  +            fun obs -> 
  +                match (findMeasure pWatts obs.SearchTerm) with
  +                | None -> 0.
  +                | Some(v) ->
  +                    match (findMeasure pVolts obs.Product.Title) with
  +                    | None -> -1.0
  +                    | Some(r) -> closeness 0.5 v r
  
positive.code:     let stopwords = set [ "and"; "or"; "the"; "a"; "an"; "of" ]
      let removeStopwords (text:string Set) = Set.difference text stopwords
  
      open System.Text.RegularExpressions
  
      let matchWords = Regex(@"\w+",RegexOptions.Compiled)
  
      let wordTokenizer (text:string) =
  
negative.code: 
  module Features = 
  
      open System
      open System.Text.RegularExpressions
      open HomeDepot.Model
      open FParsec
  
      type Feature = Observation -> float
  
  