The concept of literacy itself means more than "able to read." (aka alphabetical literacy meaning word and letter recognition). Literacy is the ability to use printed and written information to function in society, to achieve one's goals, and to develop one's knowledge and potential.

International Assessment of Adult Competencies (PIAAC) has five levels. Only 50% of U.S. adults age 16 to 65 are level 3 or above.

Level 3:

>Texts at this level are often dense or lengthy and include continuous, noncontinuous, mixed, or multiple pages of text. Understanding text and rhetorical structures becomes more central to successfully completing tasks, especially navigating complex digital texts. Tasks require the respondent to identify, interpret, or evaluate one or more pieces of information and often require varying levels of inference. Many tasks require the respondent to construct meaning across larger chunks of text or perform multi-step operations in order to identify and formulate responses. Often, tasks also demand that the respondent disregard irrelevant or inappropriate content to answer accurately. Competing information is often present, but it is not more prominent than the correct information.