Reading comprehension in the context of "Natural-language understanding"

Functional illiteracy consists of reading and writing skills that are inadequate "to manage daily living and employment tasks that require reading skills beyond a basic level". Those who read and write only in a language other than the predominant language of their environs may also be considered functionally illiterate in the predominant language. Functional illiteracy is contrasted with illiteracy in the strict sense, meaning the inability to read or write complete, correctly spelled sentences in any language. The opposite of functional illiteracy is functional literacy, literacy levels that are adequate for everyday purposes, and adequate reading comprehension, the ability to read collections of words (such as sentences and documents) and comprehend most or all of their meaning.

The characteristics of functional illiteracy vary from one culture to another, as some cultures require more advanced reading and writing skills than do others. In languages with phonemic spelling, functional illiteracy might be defined simply as reading too slowly for practical use, an inability to effectively use dictionaries and written manuals, and other factors. Sociological research has demonstrated that countries with lower levels of functional illiteracy among their adult populations tend to be those with the highest levels of scientific literacy among the lower stratum of young people nearing the end of their formal academic studies. This correspondence suggests that the capacity of schools to ensure students attain the functional literacy required to comprehend the basic texts and documents associated with competent citizenship contributes to a society's level of civic literacy.

Readability is the ease with which a reader can understand a written text. The concept exists in both natural language and programming languages though in different forms. In natural language, the readability of text depends on its content (the complexity of its vocabulary and syntax) and its presentation (such as typographic aspects that affect legibility, like font size, line height, character spacing, and line length). In programming, things such as programmer comments, choice of loop structure, and choice of names can determine the ease with which humans can read computer program code.

Higher readability in a text eases reading effort and speed for the general population of readers. For those who do not have high reading comprehension, readability is necessary for understanding and applying a given text. Techniques to simplify readability are essential to communicate a set of information to the intended audience.

Phonemic awareness is a part of phonological awareness in which listeners are able to hear, identify and manipulate phonemes, the smallest mental units of sound that help to differentiate units of meaning (morphemes). Separating the spoken word "cat" into three distinct phonemes, /k/, /æ/, and /t/, requires phonemic awareness. The National Reading Panel has found that phonemic awareness improves children's word reading and reading comprehension and helps children learn to spell. Phonemic awareness is the basis for learning phonics.

Phonemic awareness and phonological awareness are often confused since they are interdependent. Phonemic awareness is the ability to hear and manipulate individual phonemes. Phonological awareness includes this ability, but it also includes the ability to hear and manipulate larger units of sound, such as onsets and rimes and syllables.