To train a classifier one needs to add positive and negative examples of the concept that is to be learned. One way to add positive (negative) examples is to select an existing crawl and then marking that all (respectively, none) are in the class using the drop down below.

Another way to give examples is to pick an existing crawl, leave the dropdown set to label by hand. Then type some keywords to search for in the crawl you picked using the Keyword textfield and click Load . This will bring up a list of search results together with links In Class , Not in Class , and Skip . These can then be used to add positive or negative examples.

When you are done adding example, click Finalize to have Yioop actually build the classifier based on your training.