Table 2 Dream categorization rules and examples of their application

If original classifications are analogous or fit into the standard definitions, then a direct mapping of the classifications is acceptable.

A study investigating dream recall categorized their dream reports as “Recall”, “No recall” and “White dream”. Here, these can be mapped to DREAM classifications “Experience”, “No experience” and “Experience without recall”.

If original classifications fit into none or more than one of the standard definitions—but the raw reports contain data that allow for reclassification—then a reclassification is provided in addition to the original classifications.

A study investigating dream recall categorized their dream reports as “Recall” and “No recall”. As their raw dream report data were collected as free verbal reports, the “No recall” reports here can be reclassified to either “No experience”, or “Experience without recall”.

If original categories do not fit into the standard definitions unambiguously—and the raw reports do not contain data that allow for reclassification—then the original classification is provided, and its categories are interpreted as the combination of all standard definitions that could apply to it.

A study investigating dream recall categorized their dream reports as “Recall” and “No recall”. Raw dream report data provided no additional information to allow recategorization of “No recall” reports to neither “No experience” nor “Experience without recall”. Here, “Recall” can be mapped to the DREAM classification “Experience”, and “No recall” can be mapped to the combined classification “Experience without recall or No experience”.