1

Preparing for Life Beyond Prison Walls: 

The Literacy of Incarcerated Adults Near Release

Authors 

Andrea Amodeo 

Ying Jin 

Joanna Kling 

American Institutes for Research

June 2009 

Contents 

Introduction........................ 1

Profile of Incarcerated 

Adults Who Were Near 

Release................................. 2

Background 

Characteristics................. 2

Prose and Quantitative 

Literacy........................... 3

Profile of Incarcerated 

Adults Who Were Near 

Release With Low Prose 

Literacy ............................... 4

Background 

Characteristics................. 4

Characteristics Most 

Associated With Low Prose 

Literacy Among 

Incarcerated Adults Who 

Were Near Release ............. 6

Summary............................. 7

References........................... 7

Appendix A: Methodology 

and Technical Notes ....... A-1

Descriptions of 

Background Variables. A-1

Statistical Procedures.. A-2

Estimation of Literacy 

Proficiency.................. A-3

Introduction 

During the past 20 years, the United States’ population of incarcerated adults has dramatically 

increased. Since 1980, this population has increased by approximately 334 percent; more than 2.1 

million individuals were in jails or prisons in 2006 (Bureau of Justice Statistics 2006). In 2007, 

there were an estimated 509 sentenced prisoners per 100,000 U.S. residents (Bureau of Justice 

Statistics 2007). This population clearly represents a large number of U.S. adults, many of whom 

will be released and re-entering the job market and life in general. Inmates released from prison 

who lack literacy skills may find it difficult to adjust to life beyond a correctional institution. To 

help incarcerated adults succeed after their release, it is important that they have the literacy 

required to find and retain employment and to manage everyday tasks. 

Using data collected from the 2003 National Assessment of Adult Literacy (NAAL), this report 

examines the literacy of incarcerated adults who indicated that they were scheduled to be released 

within two years, or “near release,” for the purposes of this report. The computation of a release 

date is a complex one that may be recalculated continually on the basis of a variety of factors such 

as state statutes, court decisions, sentence length versus expected time served, and inmate 

behavior. For this report, the concept of near release is based on the self-reported release date 

provided by respondents and therefore may not reflect an accurately calculated anticipated release 

date. Many analyses using the full sample of all incarcerated adults were conducted as part of the 

Literacy Behind Bars: Results From the 2003 National Assessment of Adult Literacy Prison 

Survey report (Greenberg, Dunleavy, and Kutner 2007). However, the analyses described in this 

report look specifically at the characteristics of inmates who reported that they were near release, 

compare the literacy of incarcerated adults who were near release with the literacy of adults in the 

general population, and identify the characteristics of inmates near release that are most 

associated with low literacy. Many of the background variables examined in this report are based 

on self-reported data, and because many of the variables are related to one another, complex 

interactions and relationships among them cannot be explored. Therefore, readers are cautioned 

not to draw causal inferences based solely on the results presented here. 

The 2003 NAAL assessed the English literacy of incarcerated adults for the first time since 1992. 

The assessment was administered to approximately 1,200 inmates (ages 16 and older) in state and 

federal prisons, as well as to approximately 18,000 adults (ages 16 and older) living in 

households. In the prison sample, 702 inmates were near release (i.e., within two years of 

release). In addition to assessing the literacy skills of respondents, the NAAL gathered extensive 

background information on their demographic and socioeconomic characteristics (e.g., age, 

gender, country of birth, schooling), as well as on their literacy practices. 

The NAAL measured respondents’ proficiency on three literacy scales: prose, document, and 

quantitative. Proficiency was measured on a scale that ranged from 0 to 500. Scores on each of 

the three literacy scales were characterized in terms of four literacy proficiency levels: Below 

Basic, Basic, Intermediate, and Proficient.

1

 These analyses focused on the prose and quantitative 

literacy scales; in some sections, the analyses focused on the prose literacy scale only. A detailed 

description of background variables and methodology used in this report is provided in Appendix 

A: Methodology and Technical Notes. 

 

1 For an interpretation of the literacy scales and performance levels on the NAAL prison assessment, see Greenberg, E., Dunleavy, E., and Kutner, 

M. (2007). Literacy Behind Bars: Results From the 2003 National Assessment of Adult Literacy Prison Survey (NCES 2007-473). U.S. Department 

of Education. Washington, DC: National Center for Education Statistics.
2

Profile of Incarcerated Adults Who Were Near 

Release 

Background Characteristics 

Demographic Characteristics 

As shown in Table 1, incarcerated adults who were near 

release tended to be male, ages 25-39, and U.S. natives. More 

than 90 percent of the incarcerated adults near release were 

males and only 9 percent were females. The majority (51%) 

of incarcerated adults near release were ages 25-39. Fortyfive percent of incarcerated adults near release were Black and 

35 percent were White. A higher percentage of White 

incarcerated adults were near release compared with White 

incarcerated adults not near release. As found in the Literacy 

Behind Bars report for all incarcerated adults, there were more 

Blacks (nearly half of both those near release and those not 

near release) in the population of incarcerated adults than in 

the general household population. 

Table 1. Percentage distribution of incarcerated adults near 

release, incarcerated adults not near release, and the 

household population, by selected characteristics: 2003 

Characteristic 

Incarcerated 

adults 

near release 

Incarcerated 

adults 

not near 

release 

Household 

adults 

Gender 

Male 91 97 48* 

Female 9 — 52* 

Age 

16-24 18 13 17 

25-39 51 52 27* 

40-49 25 26 20* 

50 or older 6 9 36* 

Race/ethnicity 

White 35 27* 71* 

Black 45 48 11* 

Hispanic 16 19 12 

Other — — 6 

Country of birth 

U.S. 92 90 86* 

Other 8 10 14* 

Language spoken before 

starting school

English only or 

with other 91 90 87* 

Other only 9 10 13* 

Self-assessment: Understand 

English when it is spoken to you

Very well 80 72* 83 

Well 18 23* 12* 

Not well — — 3 

Not at all — — 1 

See notes at end of table. 

Table 1. Percentage distribution of incarcerated adults near 

release, incarcerated adults not near release, and the 

household population, by selected characteristics: 2003—

Continued 

Characteristic 

Incarcerated 

adults 

near release 

Incarcerated 

adults 

not near 

release 

Household 

adults 

Self-assessment: Speak English 

Very well 71 68 77* 

Well 25 27 18* 

Not well — — 4 

Not at all — — 2 

Self-assessment: Read English 

Very well 66 58* 76* 

Well 24 33* 17* 

Not well 8 — 5* 

Not at all — — 2 

Self-assessment: Write in English 

Very well 61 52* 70* 

Well 27 35* 21* 

Not well 10 9 6* 

Not at all — — 3 

Highest educational attainment 

Less than/some 

H.S. 35 40 19* 

H.S grad/GED or 

equivalency 

diploma 41 42 31* 

Postsecondary 24 18* 51* 

Have you used a computer? 

Yes 26 24 77* 

No 74 76 24* 

Computer literacy 

At least some 

computer literacy 16 14 70* 

No computer 

literacy 84 86 30* 

*Significantly different from incarcerated adults who were near release at 

the significance level of .05. 

— Sample size is insufficient to permit a reliable estimate. 

NOTES: Percentages may not sum to 100 because of rounding. The 

"Other" category includes Asians, Pacific Islanders, Native Hawaiians, 

American Indians, Alaska Natives, and Multiracial adults. 

The large majority of all incarcerated adults were native to the 

United States; however, a higher percentage of incarcerated 

adults near release were born in the United States than adults 

in the household population. The large majority of all 

incarcerated adults reported that they learned English only or 

with another language prior to starting school. 

The NAAL respondents were asked to self-assess their 

English proficiency in terms of how well they understood 

English when spoken to and how well they spoke, read, and 

wrote English. The large majority of incarcerated adults near 
3

release reported that they spoke, read, wrote, and understood 

spoken English “very well” or “well.” Higher percentages of 

incarcerated adults near release reported that they read and 

wrote English “very well” than inmates not near release. 

However, a smaller percentage of inmates near release 

reported that they read and wrote English “very well” than 

adults in the household population. 

Highest Educational Attainment and Computer Literacy 

Thirty-five percent of incarcerated adults near release had 

attained less than/some high school education. Forty-one 

percent of adults in this group had earned a high school 

diploma, General Educational Development (GED) certificate, 

or equivalency diploma. Compared with adults living in 

households, a higher percentage of incarcerated adults near 

release had a high school diploma, GED certificate, or 

equivalency diploma and a lower percentage of inmates near 

release (24%) had postsecondary education. A higher 

percentage of inmates near release had attained a 

postsecondary education than inmates not near release. 

Approximately three-quarters of all inmates reported that they 

had not used a computer. This is considerably different from 

the household population, in which more than three-quarters 

(77%) reported they had used a computer. Similar to these 

results, the majority of incarcerated adults were not computer 

literate: 84 percent of those who were near release and 86 

percent of those who were not near release. A smaller 

percentage (30%) of adults in the household population was 

not computer literate. 

Prison Experiences 

The NAAL prison background questionnaire collected data 

from respondents on various types of prison experiences. 

With regard to classes about life and career skills, the group of 

inmates near release was nearly split in reported participation, 

as shown in Table 2: 47 percent had not taken any of these 

types of classes, whereas 54 percent had taken at least one 

class. A higher percentage of incarcerated adults who were 

near release reported taking at least one class compared to 

those who were not near release. 

Comparable to the results of the Literacy Behind Bars report 

for all incarcerated adults, approximately two-thirds of the 

incarcerated adults who were near release had work 

assignments at the time of the assessment. Among this group, 

54 percent reported that they “never” read and 57 percent 

reported they “never” wrote as part of their prison job(s). 

One-third (34%) of these individuals reported that they read 

and 23 percent that they wrote “every day” as part of their 

job(s). Excluding prison work assignments, 73 percent of 

incarcerated adults near release had not been a student in a 

vocational training program since their most recent admission 

to prison. 

As expected, and shown in Table 2, the majority (76%) of 

inmates near release had the shortest expected sentences (60 

months or less). By contrast, 59 percent of incarcerated adults 

not near release were those with expected sentences of 121 

months or longer. Fifteen percent of inmates not near release 

were sentenced to 61-120 months. 

Table 2. Percentage distribution of incarcerated adults near 

release and incarcerated adults not near release, by 

selected prison experience characteristics: 2003 

Characteristic 

Incarcerated 

adults near 

release 

Incarcerated 

adults 

not near 

release 

Life and career skills classes 

Yes 54 46* 

No 47 54* 

Currently have any work assignments 

Yes 67 70 

No 33 30 

Read as part of your current job (s) 

in prison 

Every day 34 35 

Less than every day 13 17 

Never 54 48 

Write as part of your current 

job(s) in prison 

Every day 23 27 

Less than every day 20 19 

Never 57 54 

In vocational training program in prison 

Yes 27 32 

No 73 68 

Length of sentence 

0-60 months 76 12* 

61-120 months 15 30* 

121 months or more 9 59* 

*Significantly different from incarcerated adults who were near 

release at the significance level of .05. 

NOTE: Percentages may not sum to 100 because of rounding. 

Prose and Quantitative Literacy 

Estimates of the mean prose and quantitative literacy scores of 

incarcerated adults near release and not near release, along 

with estimates of the mean scores for the household 

population, are displayed in Figure 1. The mean prose and 

quantitative literacy scores of the incarcerated adults who 

were near release and incarcerated adults not near release were 

equal. However, as reported in the Literacy Behind Bars

report for all incarcerated adults, both the mean prose and 

quantitative literacy scores of the incarcerated adults who 

were near release were lower than those of the general 

household population. 
4

The literacy scores can also be used to assign individuals to 

one of the four levels of literacy performance. The percentage 

distributions across proficiency levels on prose and 

quantitative scales are displayed in Figure 2. With regard to 

prose literacy, inmates near release and inmates not near 

release had nearly the same distributions among the four 

proficiency levels. More than half of the incarcerated adults 

near release had Below Basic or Basic prose literacy: 15 

percent of those near release had Below Basic and 41 percent 

of those near release had Basic prose literacy. 

Thirty percent of inmates near release had Below Basic

quantitative literacy, and nearly half (47%) of this group had 

Basic quantitative literacy. Significantly smaller percentages 

of the household population had Below Basic or Basic

quantitative literacy than did incarcerated adults who were 

near release. 

Profile of Incarcerated Adults Who Were Near 

Release with Low Prose Literacy 

This section compares the characteristics of incarcerated 

adults who were near release with the two lowest prose 

proficiency levels (i.e., Below Basic and Basic), referred to as 

the lower literacy or less literate group in this report, with the 

characteristics of those with Intermediate and Proficient prose 

literacy, referred to as the higher literacy or more literate 

group. Special focus was paid to the incarcerated adults near 

release with lower literacy because they were considered to be 

of the greatest interest in terms of potential literacy 

interventions that would improve their skills and 

employability upon release. 

Background Characteristics 

Demographic Characteristics 

Table 3 shows selected demographic characteristics of lower 

literacy incarcerated adults near release in comparison to 

lower literacy adults not near release and lower literacy adults 

in the general household population. 
5

Table 3. Percentage distribution of incarcerated adults near 

release with low prose literacy, adults not near release 

with low prose literacy, and the household population 

with low prose literacy, by selected characteristics: 2003

Characteristic 

Incarcerated 

adults near 

release with 

low prose 

literacy 

Incarcerated 

adults not 

near release 

with low 

prose 

literacy 

Household 

adults with 

low prose 

literacy 

Age 

16-24 19 13 17 

25-39 47 50 24* 

40-49 29 26 17* 

50 or older 5 11* 42* 

Race/ethnicity 

White 25 21 54* 

Black 53 49 18* 

Hispanic 19 26 22 

Other — — 6 

Country of birth 

U.S. 87 85 76* 

Other 13 15 24* 

Language spoken before starting 

school 

English only or 

with other 88 85 76* 

Other only 12 16 24* 

Self-assessment: Understand English 

when it is spoken to you 

Very well/well 98 92 89* 

Not well/not at all — — 11 

Self-assessment: Speak 

English 

Very well/well 94 91 87* 

Not well/not at all — — 13 

Self-assessment: Read 

English

Very well/well 83 83 84 

Not well/not at all 17 18 16 

Self-assessment: Write in 

English

Very well/well 81 78 80 

Not well/not at all 19 22 20 

Highest educational 

attainment 

Less than/some 

H.S. 51 58 34* 

H.S. grad/GED or 

equivalency 

diploma 33 33 38 

Postsecondary 16 9* 28* 

See notes at end of table.

Table 3. Percentage distribution of incarcerated adults near 

release with low prose literacy, adults not near release 

with low prose literacy, and the household population 

with low prose literacy, by selected characteristics: 

2003—Continued

Characteristic 

Incarcerated 

adults near 

release with 

low prose 

literacy 

Incarcerated 

adults not 

near release 

with low 

prose 

literacy 

Household 

adults with 

low prose 

literacy 

Have you used a 

computer?

Yes 24 21 57* 

No 76 79 43* 

Computer literacy 

At least some 

computer literacy 14 12 48* 

No computer 

literacy 86 88 52* 

*Significantly different from incarcerated adults who were near release at 

the significance level of .05. 

— Sample size is insufficient to permit a reliable estimate. 

NOTES: Percentages may not sum to 100 because of rounding. The 

"Other" category includes Asians, Pacific Islanders, Native Hawaiians, 

American Indians, Alaska Natives, and Multiracial adults. 

Nearly half (47%) of the lower literacy inmates who were near 

release were ages 25-39 and 29 percent were ages 40-49. 

There was a greater number of lower literacy incarcerated 

adults near release ages 25-39 and ages 40-49 than their lower 

literacy counterparts in the household population. A higher 

percentage of inmates not near release with lower prose 

literacy than those near release with lower prose literacy were 

age 50 or older. 

Among lower literacy incarcerated adults near release, 53 

percent were Black, 25 percent were White, and 19 percent 

were Hispanic. In comparison to the less literate household 

population, Blacks were overrepresented and Whites were 

underrepresented among lower literacy incarcerated adults 

near release. Specifically, a considerably smaller percentage 

of lower literacy inmates near release were White than in the 

lower literacy household population. A higher percentage of 

less literate incarcerated adults who were near release were 

Black (53%) than in the less literate household population 

(18%). 

The large majority (87%) of lower literacy incarcerated adults 

near release were born in the United States. A higher 

percentage of lower literacy incarcerated adults near release 

were born in the United States than those with lower literacy 

in the household population (76%). 

Eighty-eight percent of lower literacy adults near release 

spoke English (only or with another language) as their first 

language. A higher percentage of lower literacy incarcerated 

adults near release spoke English (only or with another 
6

language; 88%) than those with lower literacy in the 

household population (76%). 

Interestingly, with regard to their abilities to understand 

English when spoken to and to speak, read, and write English, 

overall, lower literacy incarcerated adults near release tended 

to overestimate their abilities, as shown in Table 3. 

Specifically, lower literacy incarcerated adults near release 

had significantly more favorable self-assessments (i.e., “very 

well” and “well” responses) of their abilities to understand 

English when spoken to and to speak and read English than 

adults in the less literate household population. This has 

potential implications for literacy-related programming 

because such programs are often voluntary. If incarcerated 

adults with lower literacy are unable to recognize their need 

for literacy-based improvements, they may not elect to 

participate in such programs. 

Highest Educational Attainment and Computer Literacy 

More than half of all lower literacy inmates had attained less 

than/some high school education. One third of the lower 

literacy inmates who were near release and inmates not near 

release had a high school diploma, GED certificate, or 

equivalency diploma. A higher percentage of lower literacy 

inmates near release had less than/some high school than 

adults with lower literacy in the household population. 

Approximately three-quarters of lower literacy inmates near 

release had not used a computer. A considerably higher 

percentage (57%) of adults in the household population had 

used a computer. Eighty-six percent of lower literacy 

incarcerated adults near release were not computer literate. 

The percentage of less literate incarcerated adults near release 

who were not computer literate was considerably higher than 

that of less literate adults in the household population. 

Prison Experiences 

As shown in Table 4, inmates with both low and high prose 

literacy shared similar profiles. Sixty-four percent of lower 

literacy incarcerated adults near release had a work 

assignment in prison. Among those in this group with work 

assignments, slightly more than one-third (35%) read “every 

day” as a part of their job(s). Fifty-three percent of those in 

this group “never” read as part of their jobs. Fifty-five percent 

of those with work assignments and lower prose literacy 

reported that they “never” wrote as part of their job(s). 

Seventy-four percent of lower literacy incarcerated adults who 

were near release had not participated in vocational training in 

prison. Three-fourths of lower literacy, near-release 

incarcerated adults had a prison sentence of 60 months or less. 

Table 4. Percentage distribution of incarcerated adults near 

release with low prose literacy and incarcerated 

adults near release with high prose literacy, by 

selected prison experience characteristics: 2003 

Characteristic 

Incarcerated 

adults near 

release with 

low prose 

literacy 

Incarcerated 

adults near 

release with 

high prose 

literacy 

Currently have any work assignments

Yes 64 70 

No 36 30 

Read as part of your current job(s) 

in prison

Every day 35 32 

Less than every day 12 13 

Never 53 55 

Write as part of your current job(s) 

in prison 

Every day 22 25 

Less than every day 24 15* 

Never 55 60 

In vocational training program 

in prison 

Yes 26 27 

No 74 73 

Length of sentence 

0-60 months 75 78 

61-120 months 16 14 

121 months or more 9 8 

*Significantly different from incarcerated adults who were near release 

at the significance level of .05. 

NOTE: Percentages may not sum to 100 because of rounding. 

Characteristics Most Associated with Low 

Prose Literacy Among Incarcerated Adults Who 

Were Near Release 

To identify characteristics most associated with the low prose 

literacy of incarcerated adults near release, we conducted 

multivariate analyses (see Appendix A for details on the 

methodology). Such analyses allowed us to disentangle 

differences in the characteristics among incarcerated adults 

near release with Below Basic, Basic, and Above Basic (i.e., 

Intermediate and Proficient) prose literacy. 

In general, among the factors investigated, educational 

attainment, race/ethnicity, and being foreign- or native-born 

were found to be associated with the literacy level of 

incarcerated adults near release. 
7

For example, inmates near release who lacked a high school 

diploma or a GED certificate were, not surprisingly, nearly 

four times more likely than those who had received 

postsecondary education to have Below Basic prose literacy 

relative to Above Basic prose literacy. A similar pattern was 

found between these two educational groups with regard to 

their likelihood of having Basic over Above Basic literacy. 

Similarly, foreign-born inmates were nearly three times more 

likely than their native-born counterparts to have Basic prose 

literacy relative to Above Basic prose literacy. Also, among 

all incarcerated adults near release, Black inmates were 1.6 

times more likely than White inmates to have Above Basic

over Basic prose literacy. 

Summary 

This report, based on the 2003 NAAL Prison Survey 

assessment data, examines the characteristics of incarcerated 

adults who were near release as well as the relationship 

between the various characteristics and English literacy 

proficiency of this population group. 

Although the focus of this report is on incarcerated adults near 

release, several findings were true of both inmates near release 

and inmates not near release. Key findings that were true of 

each subgroup are as follows: 

 Incarcerated adults had lower mean prose and 

quantitative literacy scores than adults in the 

household population. 

 More than 90 percent of incarcerated adults were 

male; this is significantly more than in the general 

household population (48%). 

 Black inmates were overrepresented in comparison to 

the household population, while White inmates were 

underrepresented. 

 Lower percentages of incarcerated adults (16% of 

those near release and 14% of those not near release) 

had at least some computer literacy than respondents 

in the household population (70%). 

 Incarcerated adults with lower literacy tended to 

overestimate their self-assessments of their abilities 

to understand English when spoken to and to speak 

and read English (i.e., with responses of “very well” 

and “well”) compared with adults in the lower 

literacy household population. 

Additional key findings in this report are as follows: 

 A higher percentage of incarcerated adults near 

release were White than incarcerated adults not near 

release. 

 Higher percentages of incarcerated adults near release 

reported that they read and wrote English “very well” 

than incarcerated adults not near release. By 

contrast, lower percentages of inmates near release 

reported they read and wrote English “very well” 

than adults in the general household population. 

 As expected, similar percentages of incarcerated 

adults who were near release and those who were not 

near release had less than a high school diploma, 

GED certificate, or equivalency diploma. 

 A higher percentage of incarcerated adults who were 

near release reported taking at least one class related 

to life and career skills in prison than those who were 

not near release. 

 Two-thirds of incarcerated adults who were near 

release had work assignments. Among this group, 54 

percent reported that they “never” read and 57 

percent reported they “never” wrote as part of their 

prison job(s). 

 The majority (76%) of inmates near release had the 

shortest expected sentence lengths (60 months or 

less). By contrast, half (50%) of incarcerated adults 

not near release were those with expected sentences 

of 121 months or longer. 

 Approximately three-quarters of lower literacy 

incarcerated adults near release had not used a 

computer and 86 percent were not computer literate. 

 Among inmates near release, inmates who lacked a 

high school diploma or a GED certificate, Black 

incarcerated adults, and inmates who were born 

outside of the United States were more likely to have 

low prose literacy.

References 

Allen, N. L., Carlson, J. E., and Zelenak, C. A. (1999). The 

NAEP 1996 Technical Report (NCES 1999-452). 

U.S. Department of Education. Washington, DC: 

National Center for Education Statistics. 

Bureau of Justice Statistics. (2006). Corrections Statistics.

U.S. Department of Justice. Washington, DC: 

Author. Retrieved October 9, 2006, from 

http://www.ojp.usdoj.gov/bjs/correct.htm. 

Bureau of Justice Statistics (2007). Prison Statistics: Summary 

Findings. U.S. Department of Justice. Washington, 

DC: Author. Retrieved October 13, 2008, from 

http://www.ojp.usdoj.gov/bjs/prisons.htm. 

Greenberg, E., Dunleavy, E., and Kutner, M. (2007). Literacy 

Behind Bars: Results From the 2003 National 

Assessment of Adult Literacy Prison Survey (NCES 

2007-473). U.S. Department of Education. 

Washington, DC: National Center for Education 

Statistics. 

Mislevy, R.J. (1984). Estimating Latent Distributions. 

Psychometrika, 49(3): 359–381. 

Mislevy, R.J. (1985). Estimation of Latent Group Effects. 

Journal of the American Statistical Association, 

80(392): 993–997. 
8

Mislevy, R.J. (1991). Randomization-Based Inference About 

Latent Variables from Complex Samples. 

Psychometrika, 56(2): 177–196. 

Thomas, N. (1993). Asymptotic Corrections for Multivariate 

Posterior Moments with Factored Likelihood 

Functions. Journal of Computational and Graphical 

Statistics, 2(3): 309–322. 
A-1

Appendix A: Methodology and Technical Notes 

This section describes the background variables and statistical 

procedures used in this report. It also provides a brief 

explanation of the direct estimation method and the plausible 

values method used to estimate the NAAL proficiency scores. 

For information on survey methodology (e.g., sampling, data 

collection, weighting and variance estimation, scaling) for the 

NAAL, see Literacy in Everyday Life: Results from the 2003 

National Assessment of Adult Literacy (Kutner, Greenberg, 

Jin, Boyle, Hsu, and Dunleavy 2007). 

Descriptions of Background Variables 

Age 

All respondents were asked to report their birthdates, and this 

information was used to calculate their age. Age groups 

reported are 16 to 18, 19 to 24, 25 to 39, 40 to 49, 50 to 64, 

and 65 and older. Age groups were selected to correspond to 

key life stages of many adults: 

 16–18: Completion of secondary education 

 19–24: College or job training 

 25–39: Early career 

 40–49: Mid career 

 50–64: Late career 

 65 and older: Retirement 

Race and Ethnicity 

In 2003, all respondents were asked two questions about their 

race and ethnicity. The first question asked them to indicate 

whether they were Hispanic or Latino. Then, all respondents, 

including those who indicated they were Hispanic or Latino, 

were asked to choose one or more of the following groups to 

describe themselves: 

 White 

 Black or African American 

 Asian 

 American Indian or Alaska Native 

 Native Hawaiian or other Pacific Islander 

Individuals who responded “yes” to the first question were 

coded as Hispanic, regardless of their answer to the second 

question. Individuals who identified more than one group on 

the second question were coded as Multiracial. Respondents 

of Native Hawaiian or Pacific Islander origin were grouped 

with those of Asian origin. 

Language Spoken Before Starting School 

All respondents were asked what language or languages they 

learned to speak before starting school. Their responses were 

then used to divide respondents into five groups: English only, 

English and Spanish, English and other language, Spanish 

only, or Other language(s). The English and Spanish category 

includes adults who spoke languages in addition to both 

English and Spanish. 

Self-Assessment of English Proficiency 

The NAAL respondents were asked to assess their English 

proficiency regarding how well they understood English when 

spoken to and how well they spoke, read, and wrote English. 

Respondents assessed their proficiency in each of these skills 

by responding “very well,” “well,” “not well,” or “not at all.” 

Highest Educational Attainment 

All respondents were asked to indicate the highest level of 

education they had completed prior to their most recent 

admission to prison. The following options were provided: 

 Less than high school (0-8 years) 

 Some high school (9-12 years but did not graduate) 

 GED or high school equivalency 

 High school graduate 

 Vocational, trade, or business school after high 

school 

 College: less than 2 years 

 College: Associate’s degree (A.A.) 

 College: 2 or more years, no degree 

 College graduate (B.A. or B.S.) 

 Postgraduate, no degree 

 Postgraduate degree (M.S., M.A., Ph.D., M.D., etc.) 

Respondents who reported less than high school or some high 

school were asked how many years of education they had 

completed. For certain analyses, some of these groups were 

collapsed. 

Computer Literacy 

The NAAL background questionnaire collected data from 

respondents on performing various activities using a 

computer. Specifically, respondents were asked how often 

(every day, a few times a week, once a week, less than once a 

week, never) do they: 

 Send or receive an email message 

 Write using a word processing program 

 Use a spreadsheet program or use a financial program 

 Look up information on a CD-ROM 

 Find information on the Internet 

On the basis of these questionnaire items, a computer literacy 

scale was created such that respondents who had never 

performed any of these five computer activities were 

considered to have no computer literacy, whereas those who 

had at least some experience with at least one of the five items 

were considered to have at least some computer literacy. 

Expected Date of Release 

Inmates were asked whether they had a definite date on which 

they expected to be released, in what month and year they 

would be released, or whether they expected to ever be 

released from prison. The computation of a release date is a 

complex one that may be recalculated continually on the basis 

of a variety factors such as state statutes, court decisions, 

sentence length versus expected time served, and inmate 

behavior. Therefore, for the purposes of this report, the 
A-2

expected date of release is based solely on the respondent’s 

self-report. Using the respondent’s report, the date of release 

was categorized as two years or less or more than two years 

from the date of the interview. This variable was used to 

distinguish the “near release” and “not near release” 

subgroups, respectively. 

Participation in Life and Career Skills Classes 

The NAAL prison background questionnaire collected data 

from respondents on their participation in a variety of life 

skills courses while in prison. Specifically, the question asked 

respondents whether, since their most recent admission to 

prison, they participated in: 

 Employment counseling (including how to find a job 

or interviewing skills) 

 Classes in parenting or child rearing skills 

 Classes in life skills and community adjustment, 

including anger management, conflict resolution, 

personal finance, or other life skills 

On the basis of these questions, a life and career skills scale 

was created. Respondents who answered “yes” to any one of 

the three questions were considered to have participated in life 

and career skills classes; those who answered “no” to all three 

questions were considered to have not participated. 

Vocational Training Participation 

Inmates were asked whether since their most recent admission 

to prison they had been a student in a vocational training 

program, excluding prison work assignments, and whether 

they were currently students in a vocational training program. 

Inmates were identified as no participation, past participation, 

or current participation in vocational training in prison. 

Work Assignment 

Inmates were asked whether they currently had a prison work 

assignment. 

Reading as Part of Prison Work Assignment 

Inmates were asked to indicate how often they read as part of 

their current jobs in prison. They were given the following 

options: every day, a few times a week, once a week, less than 

once a week, or never. 

Writing as Part of Prison Work Assignment 

Inmates were asked to indicate how often they wrote as part of 

their current jobs in prison. They were given the following 

options: every day, a few times a week, once a week, less than 

once a week, or never. 

Length of Sentence 

Inmates were asked to indicate in what month and year they 

were admitted to prison most recently and whether they had a 

definite date on which they expected to be released. If they 

answered “yes” to having a definite date to be released, they 

were asked in what month and year they would be released. 

Those who did not have a definite date to be released were 

asked the month and year of their earliest possible release 

date. Their responses to these questions were used to calculate 

the length of their incarceration: 0-60 months, 61-120 months, 

121 or more months/do not expect to be released. 

Statistical Procedures 

Tests of Statistical Significance 

All comparisons discussed in this report have been tested for 

statistical significance using the t statistic. Statistical 

significance was determined by calculating a t value for the 

difference between a pair of means, or proportions, and 

comparing this value with published tables of values at a 

certain level of significance, called the alpha level. The alpha 

level is an a priori statement of the probability of inferring that 

a difference exists when, in fact, it does not. The alpha level 

used in this report is .05, based on a two-tailed test. 

Differences in the means and proportions between subgroups 

were calculated using the following t statistic: 

where p1 and p2 are the estimates to be compared and se1 and 

se2 are their corresponding standard errors. When a subgroup 

was compared to a total group, a modification of the standard 

error of difference was made to adjust for group dependence. 

The formula for the adjusted standard error of difference was 

as follows: 

where p is the proportion of the total group contained in the 

subgroup. 

Minimum Sample Sizes for Reporting Subgroup Results 

In the NAAL reports, the sample sizes were not always large 

enough to permit accurate estimates of proficiency and/or 

background results for one or more categories of variables. 

For results to be reported for any subgroup, a minimum 

sample size of 45 was required. This number was arrived at 

by determining the sample size needed to detect an effect size 

of 0.5 with a probability of 0.8 or greater, using a design effect 

of 1.5. This design effect implies a sample design-based 

variance 1.5 times that of a simple random sample. The effect 

size of 0.5 pertains to the true difference in a given mean 

estimate (e.g., mean proficiency) between the subgroup in 

question and the total population, divided by the standard 

deviation of that estimate in the total population. An effect 

size of 0.5 was chosen following Cohen (1988), who classifies 

effect size of this magnitude as “medium” as well as to be 

consistent with what was done in the 1992 National Adult 

Literacy Survey (NALS).2

 

2 Cohen, J. (1988). Statistical Power Analysis for the Behavioral 

Sciences (second edition). Hillsdale, NJ: Lawrence Erlbaum 

Associates. 
A-3

Multinomial Logistic Regression Analyses 

Proficiency on the NAAL literacy scales (i.e., prose, 

document, and quantitative) is measured on a scale that ranges 

from 0 to 500. The performance of adults on the assessment 

can be reported as either mean scores on the scale or on the 

basis of the distribution of adults across the NAAL 

performance levels (Below Basic, Basic, Intermediate, and 

Proficient). Each performance level describes the abilities 

associated with score ranges on the NAAL scale. 

In investigating the effects of multiple factors on low literacy 

for incarcerated adults, we conducted multinomial logistic 

regression analyses. Such analyses allowed us to disentangle 

differences between the characteristics of incarcerated adults 

near release with Below Basic literacy and those of 

incarcerated adults near release with Basic literacy, while 

holding constant a series of other explanatory variables. 

Similarly, it also allowed us to examine differences between 

the characteristics of incarcerated adults near release with 

Basic literacy and those with literacy levels in the next highest 

categories (Intermediate and Proficient). 

Multinomial logistic regression is a form of regression used 

when the dependent variable is categorical with more than two 

classes and the independent variables are of any type.3

 It 

allows the simultaneous comparison of more than one contrast 

(e.g., the probability of Below Basic vs. Basic literacy, Basic

vs. Above Basic literacy, Below Basic vs. Above Basic 

literacy) and usually expresses the impact of predictor 

variables on dependent variables in terms of odds ratios. 

The odds ratio for a given independent variable represents the 

factor by which the odds change in the dependent variable for 

a one-unit change in the independent variable. For example, if 

the odds ratio for success in a given performance test for 

females versus male is 3.5, and if this odds ratio is statistically 

significant, we would say that the odds of success for females 

are 3.5 times as large as for males. 

The statistical significance of the odds ratio estimates are 

indicated by the confidence interval for the odds ratio. If the 

confidence interval around the odds ratio contains the value of 

1.0, then the change in the value of the independent variable is 

not associated with change in the odds of the dependent 

variable. Thus, that independent variable is not considered a 

useful predictor in the logistic model. 

 

3

 For more information on multinomial logistic regression, see 

Hosmer, D., and Lemeshow, S. (2004). Applied Logistic Regression. 

New York: John Wiley & Sons.

In our multinomial logistic regression analyses, the outcome 

measure was the NAAL literacy performance level: Below 

Basic, Basic, and Above Basic (i.e., Intermediate and 

Proficient combined). Using the literacy levels rather than the 

NAAL scale scores as the dependent variables in the model 

made the analyses more easily interpretable. If the continuous 

NAAL scale scores had been used, the results would need to 

be discussed in terms of unit changes on the NAAL scale per 

unit change in an independent variable. The impact of specific 

variables would be more difficult to grasp in this approach, 

given the abstract nature of the NAAL scale. The predictor 

variables in the model were age, race/ethnicity, language 

spoken before starting school, country of birth, educational 

attainment, participation in basic skills training, participation 

in life and career skills classes, prison work assignments, 

participation in vocational training in prison, length of 

sentence, computer literacy, and oral passage reading scores as 

measured in Fluency Addition to NAAL.4

Table A-1 reports the odds ratio estimates from the 

multinomial regression of the prose literacy performance level 

on the set of predictor variables described above. 

Estimation of Literacy Proficiency 

The NAAL used a complex assessment design that allowed 

maximum coverage of the broad domain of literacy while 

minimizing the time burden on any one respondent. Under 

this design, the NAAL administered only a fraction of the 

assessment items on each literacy scale to each respondent. 

Although individual respondents were required to take only a 

small portion of the entire pool of assessment questions, the 

aggregate results across the entire assessment allowed broad 

reporting of literacy for the targeted population. However, 

because respondents did not receive enough literacy tasks to 

provide reliable information about individual performance, 

traditional test scores for individual respondents would have 

resulted in biased estimates of population characteristics and 

therefore were not appropriate to use for estimates of 

population statistics. 

 

4

 As part of the NAAL assessment, adults were asked to read a series 

of short passages aloud. Their responses were recorded and later 

scored for accuracy and speed.
A-4

Table A.1. Odds ratio estimates from multinomial regression for incarcerated adults near release

Below Basic vs. Basic Basic vs. Above Basic Below Basic vs. Above Basic 

Effect 

Point 

Estimate 

95% Wald 

Confidence 

Limits 

Point 

Estimate 

95% Wald 

Confidence 

Limits 

Point 

Estimate 

95% Wald 

Confidence 

Limits 

Race/ethnicity: Black vs. White -- -- -- 1.62 1.05 2.51 -- -- -- 

Country of birth: Foreign vs. U.S. -- -- -- 2.89 1.00 8.40 -- -- -- 

Education: Less than/some high school 

vs. Postsecondary -- -- -- 2.58 1.40 4.77 3.94 1.51 10.34 

Oral passage reading score 0.98 0.97 0.99 0.99 0.99 1.00 0.97 0.96 0.98 

-- Estimates not significant and not shown. 

Note: Results were only shown for predictors with significant odds ratio estimates. 

To obtain unbiased estimates of population statistics (e.g., 

subgroup means or percentages in each proficiency level), the 

NAAL used methods derived from Marginal Maximum 

Likelihood (MML) estimation. Such MML estimation 

procedures were available with AM software.5

 Estimates for 

average literacy scores and percentages in each literacy 

proficiency level in this report were all obtained using the 

direct estimation method with AM. The multinomial logistic 

regression analyses could not be conducted using MML direct 

estimation because the procedure is not available in AM. 

Instead, an alternative estimation procedure called plausible 

values methodology was used for the multinomial logistic 

regression analyses. Plausible values were initially developed 

for the National Assessment of Educational Progress (NAEP; 

Mislevy 1984, 1985, 1991; Thomas, 1993) to allow secondary 

users to estimate statistics derived from individual data. 

Plausible values are multiple imputations randomly drawn 

from a distribution derived from the MML parameter 

estimates for an extensive conditioning model (Allen, Carlson, 

and Zelenak 1999). 

It is important to recognize that plausible values are not test 

scores for individual, and they should not be treated as such. 

Plausible values are randomly drawn from the distribution of 

scores that could be reasonably assigned to each individual. 

As such, the plausible values contain random error variance 

components and are not optimal as scores for individuals. 

 

5

 For more information on direct estimation methodology followed 

for NAAL and the use of AM, see Baldi, S. (Ed.) et al. 

(Forthcoming). Technical Report and Data File User’s Manual for 

the 2003 National Assessment of Adult Literacy. U.S. Department of 

Education. Washington, DC: National Center for Education Statistics.

In our multivariate analyses, five plausible values for each 

adult were obtained as estimates of scores on the prose literacy 

scale. These plausible values were then used to assign each 

individual to one of the NAAL performance levels. Five sets 

of multinomial regression analysis were conducted, using each 

of the five plausible values. The reported odds ratio estimates 

are the average of the five odds ratio estimates using each of 

the five plausible values. It should be noted, however, that the 

standard errors used in the significance tests for the reported 

odds ratio estimates were not adjusted for variation among the 

five sets of results given the complexity of the computations 

and the unavailability of an estimation procedure in the 

statistical software. Therefore, the confidence limits around 

the odds ratio estimates might be narrower than they would be, 

had the standard errors been corrected.