The document discusses machine learning algorithms for symbol-based learning. It introduces a general framework for symbol-based learning that includes representing data and goals, representation languages, operations for manipulating representations, concept spaces to search, and heuristics for guiding the search. It then describes two specific algorithms: version space search and ID3 decision tree induction. Version space search uses a candidate elimination algorithm to iteratively generalize from positive examples and specialize from negative examples to identify the target concept.