Data: Factual information (e.g., measures) collected in a study that is the basis for scientific claims or assertions (e.g., narratives about data or papers). The more granular the features (i.e., the greater the number of possible values or states of a variable), the more information contained by the data.

Variable: Measure, quantity, or element that defines a set of data collected in a study.

Individual Participant Data (IPD): Data that is available at the level of the individual participant (human) or subject (animal) in a study, constituting the smallest independent unit of analysis. IPD data is used to produce aggregated summary measures for groups of subjects (e.g., mean; standard deviation).

Data Sharing: The process by which data are made available to others for (re)use. Manuscript publication and statistical reports are not considered Data, but rather narratives about and summaries of data.

FAIR: Stewardship principles that state that data must be findable, accessible, interoperable, and reusable, providing a guided framework on how to share data on the Web (Wilkinson et al., 2016).

Standards and standardization: Data standards are rules and specifications to assure consistency and regularity in collection of data. Standardization is the process of conforming data to concrete standards.

Data harmonization: The process by which data from different sources and studies are transformed to make them as comparable as possible, with the goal of integrating them together. This may include changes in naming conventions, statistical transformations, data reformatting, semantic crosswalking, among others.

Data integration or pooling: The act of combining data from different sources that are deemed comparable, either after the results of data harmonization, or by a priori study design. We refer to pooling and integration interchangeably.

Semantic interoperability: The capacity to integrate data that have the same meaning. A variable collected in different studies that has the same meaning across studies is said to have semantic interoperability. Common terminologies and vocabulary can set standards for semantic interoperability.

Data format interoperability: The capacity to exchange data because they are formatted in the same way or in forms that can be interchanged (mapped to each other). Format interoperability can be promoted using the same formatting standard. Note, format interoperability does not guarantee semantic interoperability.