As you are looking at dictionaries for your children, be sure and consider the following before buying a dictionary: book design and layout, the size of the type face and the weight of the paper, the clarity of the definitions for the age level targeted, the type and amount of additional reference and word usage/history information provided, the overall organization, the illustrations, and the maturity of your child.
Children's dictionaries are generally designed for the child who is an upper elementary or middle school student. They usually contain more illustrations than a student dictionary, and the illustrations, both photographs and artwork, are in color. This type of dictionary is particularly good for the visual learner.
Student dictionaries generally target older students, some even include high school students in their target audience. They tend to be more like adult dictionaries, although they usually have more illustrations and special sections than many dictionaries for adults.
Remember!Words are constantly being added to our vocabulary. Just think of all of the words that have come with the advent of new technologies: web site, Internet, broadband, etc. For this reason, you will want to look for the latest published edition of any dictionary you choose.