data_dfm_LBGexample: dfm from data in Table 1 of Laver, Benoit, and Garry (2003)
Description
Constructed example data to demonstrate the Wordscores algorithm, from Laver 
Benoit and Garry (2003), Table 1.Format
A dfm object with 6 documents and 37 featuresDetails
This is the example word count data from Laver, Benoit and Garry's 
  (2003) Table 1. Documents R1 to R5 are assumed to have known positions: 
  -1.5, -0.75, 0, 0.75, 1.5.  Document V1 is assumed unknown, and will have a
  raw text score of approximately -0.45 when computed as per LBG (2003).