Gives a rough positive/negative reading of a piece of text by counting known positive and negative words against a fixed list. It can miss sarcasm, negation ("not good"), and context — treat it as a loose signal, not a precise measurement.
Gives a rough positive/negative reading based on a word list — it counts known positive and negative words. It can miss sarcasm, negation ("not good"), and context, so treat the result as a loose signal rather than a precise measurement.