1. A method comprising: obtaining a word frequency of one or more words in a product title under a first category and another word frequency of the one or more words in the product title under a second category; calculating a first overall word frequency of the product title under the first category based on the word frequency of the one or more words in the product title under the first category and a second overall word frequency of the product title under the second category based on the word frequency of the one or more words in the product title under the second category; setting a first threshold for the first category and a second threshold for the second category; storing the first threshold and the second threshold in a storage device; and comparing the first overall word frequency of the product title with the first threshold and the second overall word frequency of the product title with the second threshold to determine a category of the product title.