@article{WLG11,
  author = {Ward, Jamie A. and Lukowicz, Paul and Gellersen, Hans},
  title = {Performance metrics for activity recognition},
  booktitle = {Transactions on Information Systems and Technology (TIST)},
  publisher = {ACM},
  year = {2011},
  doi = {http://doi.acm.org/10.1145/1889681.1889687}
}