Amazon calculates a product’s star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers, and factors that establish reviewer trustworthiness.
This is a good intro course, that will help a traveler. Some other courses are filled with phrases and words that a person would seldom use. This course sticks primarily with actual situations that you will encounter as a traveler to a Spanish speaking country. The method of teaching in this course is fantastic.