An unknown variable is a term used in text analytics to refer to a word or phrase that cannot be identified with certainty. This may be due to the fact that it is a proper noun, or it may simply be an uncommon word. Unknown variables can cause problems when trying to extract meaning from text, as they can disrupt the flow of information and make it difficult to determine what the text is actually talking about.
Unknown variables can also refer to:
An unknowable quantity in an equation, which must be solved for in order to find a solution.
A placeholder name used in programming when the actual name is not yet known.
A value that has not been measured or observed, but is needed in order to solve a problem.
Unknown variables can be distinguished from unidentified entities in that unknown variables are words or phrases that cannot be identified with certainty, while unidentified entities are things that cannot be identified at all. Proper nouns are a type of unknown variable, but they are not the only type. Out-of-scope concepts are ideas or topics that are not relevant to the text at hand, and thus can be safely ignored.
Uses of Unknown Variable
Unknown variables can be found in both natural language text and structured data. In natural language text, unknown variables can cause problems when trying to extract meaning from the text, as they can disrupt the flow of information and make it difficult to determine what the text is actually talking about. In structured data, unknown variables can be found in fields where the data is missing or incomplete. When dealing with missing data, it is often necessary to impute the missing values in order to make accurate predictions.
Methods of identifying Unknown Variable
There are a few different methods that can be used to identify unknown variables in text:
Part-of-speech tagging: This method uses the grammatical structure of a sentence to identify words that are likely to be unknown variables.
Named entity recognition: This method looks for named entities in text, which are likely to be proper nouns and thus unknown variables.
Conceptual density: This method measures the number of concepts mentioned in a text, and assumes that texts with a higher density of concepts are more likely to contain unknown variables.