version      date  description
1.0      07/08/10  The first version on CRAN
1.1      07/17/10  Bug fixes
2.0      12/14/10  A major update incorporating the methods proposed by Blair and Imai (2010)
2.1      01/03/11  "lm" method for list experiment linear model added and several bug fixes
2.2      01/18/11  Multi design for "lm" method implemented, several bug fixes
