The chapter by Sticht and James (1984) provides an extensive review of listening and reading studies with adults. In one study, using the same test as used to obtain the data in Figure 84, an incarcerated prison population of men reading at the 4th grade level showed about 1.5 grade levels of "potential" as derived in Figure 83.

Using a different group administered test of listening and reading skills, the Durrell Listening and Reading Series tests, Sticht (1978) reported that for 71 native speakers of English who were in an adult literacy program their average reading level was at the 4.8 grade level, while their reading "potential" (listening transformed to reading as in Figure 83) was 6.0. Interestingly, for 45 adults with English as a second language, their reading score was 4.8 while their reading "potential" score was at the 4.4 grade level. In other words, their listening skills were lower than their reading skills, so when the listening score was converted to a reading "potential" score, they performed below their actual reading level.

Using the Diagnostic Reading Scales, which are administered one-on-one as an individual test, Sticht & Beck (1976) assessed the reading "potential" of 42 native English speakers and 32 English as a second language speakers in an adult literacy program. The native speakers had an average reading level at the 6.2 grade level and a "potential" at the grade 6.4 level. The non-native English speakers read at an average 4.3 grade level and had a "potential" at the 4.4 grade level.

Generally speaking, as the data of Figure 84 and the studies cited above suggest, adults with lower levels of literacy tend to also have lower levels of oral language (listening) comprehension. This appears to be true for both vocabulary knowledge and the comprehension of connected discourse. Of course, there can be important exceptions to these general trend data. But as a rule, these data on listening and reading suggest that adult literacy educators will have to provide extensive opportunities for adult learners to develop considerable bodies of knowledge to improve both their oral and written language comprehension skills to the higher levels.

Reference

Sources for all of the studies cited above, and many others exploring listening and reading skills of adults, may be found in:

Thomas G. Sticht & J. H. James (1984). Listening and Reading. In P. Pearson, R. Barr, M. Kamil, and P. Mosenthal ( Eds.) Handbook of Reading Research. New York: Longmans.