Metatagging is the process of adding metadata to an information resource to enable search and retrieval of this resource on the web. Metadata are data about an information resource or simply data about data. More specifically, metadata describe the different characteristics and attributes of an information resource—for example, the title, the author, the date of creation, and the subject. They consist of data items that are associated with the information resources, which are called metadata elements or tags. In the field of technology-enhanced learning (TEL), metadata are used for characterizing learning objects (LOs) and apps toward facilitating their search and retrieval from learning object repositories and app markets or app stores correspondingly. An LO is any type of digital resource that can be reused to ...