Here’s a brief answer to the question, “What’s the difference between basal and guided reading instruction?”
Basal reading instruction uses a series of textbooks which have been designed or written to teach reading systematically. Basal readers have fallen out of popularity in the past 15 years or so due to their weak literary basis. The “old” basal readers used language which did not sound the way that people naturally talk, nor was it good literature. In response to this criticism, publishers have noticeably improved the literary content of basal readers.
Guided reading uses a variety of texts to teach reading, with less emphasis upon systematic, sequential instruction of phonics and more emphasis upon deriving meaning from the text. Guided reading instruction uses leveled books which correspond to the reading levels of the students, although the number of unfamiliar words can vary widely. I have seen teachers flounder with both approaches.
Both approaches do have strengths and weaknesses. Both also have passionate advocates, like me, who need to reread Crucial Conversations in order to discuss this topic without assaulting one another! As a special educator who focuses on phonological and phonemic weaknesses (which are by definition at the core of dyslexia), I prefer to begin with basal readers and decodable texts which control the number of unfamiliar words and add additional texts as kids progress. In a school with an adequate leveled book selection, it is possible to use guided reading materials effectively with special needs kids (in my case, as a supplement to specialized instruction). In response to concerns about struggling readers, the publisher of the popular Fountas and Pinnell levels texts has added Leveled Literacy Intervention and is currently investigating its long-term effectiveness.