Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Very good reference book

Just like it's predecessors, this is a very good reference book. I like the beginning of each age group, when they state what your child should be doing. It helped me keep track of where my son was developmentally. Other than that, don't bother reading it from cover to cover, since kids do things so differently. Just use the index to look up issues as they occur.