<cite>Waseem and Hovy (2016)</cite> explore several feature types: they employ n-gram features -specifically, they find that character n-grams of lengths up to 4 perform best -and in addition, they combine them with gender information, geographic location information and tweet length, finding that combining n-gram features with gender features yields slightly better results than just n-gram features do, while mixing in any of the other features results in slightly lower scores.