The document discusses the pros and cons of open educational resources (OER) that teachers should consider before using them. The pros are that OER provide free resources including lessons, activities, videos and entire courses. They encourage sharing knowledge and are accessible online. However, the cons are that there is a large quantity of OER so finding suitable resources takes time. The quality is not controlled so teachers must evaluate resources themselves. Teachers also need to understand licensing and how to share materials while maintaining licenses. Not all OER content is up-to-date and the technology requirements may limit some students. Weighing these pros and cons helps teachers make informed choices about using OER.