english | espanol
| 1865 | The ability to sign or mark one's name. |
| 1900 | The ability to do basic reading, writing and calculations |
| 1950 | The ability to read and write with understanding a short, simple statement about one's own life. |
| 2000 | The ability to use printed and written information to function in society, achieve one's goals, and develop one's knowledge and potential. |
| 2006 | Adequate information literacy, health literacy, computer/digital literacy, quantitative, and workplace literacy to manage one's life, health, and family. |