Collection content classifiers classify computer files and other collection content in accordance with predetermined classification specifications. In operation, collection content classifiers dynamically discover collection content members, assign data types to content members, associate symbolic actions with content members, determine processing dependencies among content members, and return organized classification information to calling programs for subsequent use in processing content members. Collection content classifiers thereby improve the productivity of human knowledge workers by enabling the construction of smart, collection-aware application programs that can perform more extensive, more complex, and more automated collection processing operations than were previously possible.