The NALS Literacy Levels

The NALS was the first survey of adult literacy skills to report data in terms of five levels of skill. These literacy categories are much like the categories used by the military since World War I to categorize a range of scores obtained by young adults into categories of "intelligence" (Army Alpha and Beta tests, see page 19 of this report), "general learning ability" (Army General Classification Test (AGCT), see page 25), and "trainability" (Armed Forces Qualification Test (AFQT), (see page 27).

The NALS literacy levels are important because they are to be used by the National Governor's Association and the federal government to track the nation's progress on Education Goal Number 5: making all adults literate by the year 2000 (National Education Goals Panel, 1992, pp. 40-43).

In the NALS, the five levels used to describe categories of proficiency include Level l (scale scores from 0 to 225), Level 2 (scale scores from 226 to 275), Level 3 (scale scores from 276 to 325), Level 4 (scale scores from 326 to 375), and Level 5 (scale scores from 376 to 500). For each of the prose, document, and quantitative scales, all those adults with scores from 0 to 225 were assigned to Level 1, those with scores from 226 to 275 were assigned to Level 2 and so forth. Table 4 shows the percentage of adults assigned to each of the five literacy levels for each of the three literacy scales.

Altogether, the adult population sampled represented approximately 191,000,000 adults. The data in Table 4 suggest that some 40 to 44 million adults are in the lowest level of skill, Level 1. Some 50 million are in Level 2, 61 million in Level 3, 28 to 32 million in Level 4 and 6-8 or so million adults are in Level 5.

Being assigned to one of the five levels means that people at the average skill for a given level have an 80 percent probability of being able to perform the average tasks at the given level. For instance, the NALS report indicates that a person with a skill level of 200 would be assigned to Level 1, for which the average task difficulty is about 200 (averaged across the three literacy domains). This means that the person would be expected to be able to respond correctly to 80 percent of the average tasks in Level 1. However, this same person would be expected to be able to correctly respond to over 30 percent of the tasks at Level 2, about 15 percent of the tasks at level 3, 8 percent of the tasks at Level 4 and about 5 percent of the tasks at Level 5 (Kirsch, Jungeblut, Jenkins, & Kolstad, 1993, p. 102). This results from the fact that, as indicated in the discussion of items for the YALS survey earlier, persons with skill levels below the difficulty level of an item may be able to perform the item correctly, though with a less than 80 percent probability of a correct response.

The Prose Literacy task item illustrated on page 101 shows that a person needs a skill level of 279 to have an 80 percent probability of being able to perform the item that is of 279 difficulty.