Table 1:

Term definitions.

Term	Definition
Ignorance	community/collective/scientific known unknowns
Knowledge-base	a database of known information
Ignorance-base	a knowledge-base, created from the literature, with additional annotations for the sentences that are ignorance statements
Statements of ignorance	statements of incomplete or missing knowledge categorized based on the entailed knowledge goal
Knowledge goal	the next actionable step based on the given unknown
Biomedical concept classification/recognition	automatically identifying and mapping biomedical entities to ontologies
Ontologies	controlled vocabularies with specified relationships
Open biomedical ontologies (OBOs)	an effort to create standardized ontologies for use across biological and medical domains
Lexical cue	words or phrases that signify a statement of ignorance
Taxonomy of ignorance	a categorization of ignorance statements based on the entailed knowledge goal
Exploration by topic	automatically find statements of ignorance related to a topic from the ignorance-base
Exploration by experimental results	automatically contextualize experimental results in terms of statements of ignorance from the ignorance-base to understand what questions may bear on them
Ignorance enrichment	a method to identify biomedical concepts that are over-represented in a set of ignorance statements as compared to all sentences, and thus may be a new promising avenue to explore in relation to the input topic
Ignorance-category enrichment	a method to identify ignorance categories that are over-represented in a subset of ignorance statements as compared to all ignorance statements in order to illuminate the types of knowledge goals to pursue and to map out how they change over time