def extra_sequence_validation(prediction_raw, sm)
      return 1 if prediction_raw.length != sm.length
      # find residues that are in the prediction
      # but not in the statistical model
      no_insertions = 0
      (0..sm.length - 1).each do |i|
        no_insertions += 1 if prediction_raw[i] != '-' && sm[i] == '-'
      end
      no_insertions / (sm.length + 0.0)
    end
def extra_sequence_validation(prediction_raw, sm)
      return 1 if prediction_raw.length != sm.length
      # find residues that are in the prediction
      # but not in the statistical model
      no_insertions = 0
      (0..sm.length - 1).each do |i|
        no_insertions += 1 if prediction_raw[i] != '-' && sm[i] == '-'
      end
      no_insertions / (sm.length + 0.0)
    end
Returns the percentage of extra sequences in the prediction
 with respect to the statistical model
 Params:
 +prediction+: +String+ corresponding to the prediction sequence
 +sm+: +String+ corresponding to the statistical model
 Output:
 +Fixnum+ with the score