In this project I am deriving the scale factors and efficiencies of the MV1 and MV1c tagging algorithms using a semi-leptonic and inclusive jet sample in the top anti-top dilepton channel. The selection method of the semi-leptonic jet sample uses the same cut based selection as that which is used by the "ptRel" method. The aim being to compare the scale-factors derived from both samples in order to investigate the difference seen in 2011 data.