Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Ineffective...

I agree in part with the reviewer (of another text in this series) who stated that Travessia is lacking in a structured, grammar based approach. Naturally, any textbook is going to be a poor substitute for other, more immersive ways of learning a language but Travessia tries too hard to rise above this basic fact. The result is that the texts really don't stand on their own as even a minimally useful reference/guide to the language. Worse, they tie you to dependence on the video, a circumstance that is, among other things, highly inconvenient. I found this very frustrating...as did my teacher, a native Brazilian, who--bless his heart--found creative ways to get around this constraining series of texts in his classroom.