The running record will inform me if the reading level for that day was easy, instructional or hard.
An easy book is a reading level that the student can read without support (i.e. without being told unknown words or given prompts). He / she makes very few errors and demonstrates excellent comprehension (understanding) of the book.
An instructional book is a reading level that the student can read and understand with the support of someone else. Students read with a 90-95 percent accuracy rate and understand most of what they read. At this level the students can cope with new learning as the teacher provides the needed support for challenging vocabulary and concepts, and prompts the student to use known strategies.
A hard book is a reading level that the student obviously struggles to read and errors are numerous (under a 90 per cent accuracy rate). Reading at this level only causes frustration and is to be avoided.
l do not want to pick a new book that could be too easy because there will be very little (if any) new learning and l will not be maximizing the progress of the student. The best new book to choose will be one that l think the student would be able to read at an instructional level (i.e. not too easy or too hard). An instructional book that is given a book introduction by the teacher, and rehearsed by the student, should be easy to read the next day when the running record is taken. If the book is still read at an instructional level, the student is not ready yet for the next reading level.