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Next to the actual data file, each Metapsy database repository also contains a folder in which metadata is stored. Metadata items may vary between repositories, but a core selection of files is always included. We focus on these metadata items here.

Metadata Items

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The following standard metadata items are always included in the metadata repository folder:

• 📄 authors.json: A .json file containing the authors or owners of the the database, as well as their ORCID research ID.
• 📄 last_search.txt: A .txt file containing the date of the last search update, in the YYYY-MM-DD format.
• 📄 number_studies.txt: A .txt file containing the number of studies included in the current version of the database.
• 📄 search_string.txt: A .txt file showing the employed search string(s).
• 📄 shorthand.txt: A .txt file with the metapsyData shorthand of the database.
• 📄 variable_description.json: A .json file; containing a JSON object (key-value pairs). The key represents the variable name, while the value component includes a description or explanation provided for the database variable (e.g. information on the meaning of factor levels).

There is also one additional metadata item stored at the base of the repository:

• 📄 license: A file that contains the license under which the data is shared. This is either the license text itself, or a persistent identifier to the license. By default, all datasets are assigned with a Open Data Commons Attribution License (ODC-By) v1.0 license, which allows anyone to share and adapt the data, as well as to create works from the it, provided that the original database is attributed.