for example want to make a sentiment classifier a very cheap way to do that is to simply take pre-trained word embeddings like glove or word to back you know assign each word word embedding and then just average the word embeddings okay and you count on the fact if there are a lot of kind of negative words in there like bad sad angry the word embedding kind of will you know reflect that and the average word embedding will point more into the bad direction and if there's a lot of happy words the average will point into the happy