This field suggests terms, but it is expected that the vocabulary will evolve.' label 'Interactivity Level' syntax string LearningLevel attribute description 'This field describes the difficulty of the materials. This field defines the target audience in terms of academic grade and skill level at that grade. The structure of the field terms reflects the fact that what is easy at a high academic grade is more difficult at a lower one. Specific capabilities required, such as reading proficiency in a particular language, are described in the Prerequisites field. This field is used to discover materials that are appropriate for the skill level of the learner.
Age is subsumed into grade.
Other addressing schemes can accomplish this objective. The URL is only an example. A URL implies the mechanism for retrieving the offering. For each pair, the first term is the educational objective, the second is the reference. The second term of the pair, reference, is optional.