NAEP Technical DocumentationDevelopment of the Reading Indices

For the 2015 reading assessment, several indices of policy interest were developed that satisfied both theoretical criteria based on content analysis, and empirical criteria based on multivariate statistical techniques. This resulted in the creation of several new reporting elements. The development of the 2015 reading indices can be summarized in three main steps:

1. Question selection. A content analysis of the existing subject-specific 2015 reading survey questionnaires was conducted to select sets of the questions that were theoretically interpretable and meaningful as a conceptual unit, as potential indices to measure specific constructs of interest.

2. Examination of empirical relationships. Factor analysis was used to explore and verify the empirical properties of the data. Construct validity of the potential indices was evaluated through factorial validity with respect to the survey question responses, and the convergent and discriminant validity of the factor with respect to other factors. If the factor had the expected pattern of relationships and non-relationships, the construct validity of the factor as representing the intended index was supported.

3. Index scoring. The partial credit item response theory (IRT) model was used to scale the indices. Scaling of the index items was first conducted to get the item parameters and was based on marginal maximum likelihood methodologies. After the parameters were estimated, expected a posteriori (EAP) scores were calculated as the estimate of the index score. Then, the EAP scores were transformed to have a mean of 10 and a standard deviation of 2 on a scale from 0–20.

Indices were formed for grades 8 and 12 reading, but the grade 4 survey questionnaire did not include a sufficient number of questions that would allow for the creation of indices.

Index of Students' Views on Reading

The tables below present the items forming the index of students' views on reading at grades 8 and 12, respectively. This index was designed to measure students' interest in and enjoyment of reading and their engagement in reading-related activities. Students were asked to indicate the extent to which they agreed with three statements about reading (strongly disagree, disagree, agree, or strongly agree). Two items asked students how often they engaged in reading-related activities (never or hardly ever, once or twice a month, once or twice a week, or almost every day).

Items in the index of eighth-grade students' views on reading, grade 8 reading combined national and state assessment: 2015
Please indicate how much you DISAGREE or AGREE with the following statements about reading and writing. Fill in one oval on each line.
Response categories
Item			Strongly disagree	Disagree	Agree	Strongly agree
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2015 Reading Assessment.
R833001	a.	When I read books, I learn a lot.	A	B	C	D
R833101	b.	Reading is one of my favorite activities.	A	B	C	D
R833002	c.	Reading is enjoyable.	A	B	C	D
How often do you do each of the following? Fill in one oval on each line.
Response categories
Item			Never or hardly ever	Once or twice a month	Once or twice a week	Almost every day
R833401	a.	Read for fun on your own time	A	B	C	D
R833501	b.	Talk with your friends or family about something you have read	A	B	C	D

Items in the index of twelfth-grade students' views on reading, grade 12 reading national assessment: 2015
Please indicate how much you DISAGREE or AGREE with the following statements about reading and writing. Fill in one oval on each line.
Response categories
Item			Strongly disagree	Disagree	Agree	Strongly agree
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2015 Reading Assessment.
R833001	a.	When I read books, I learn a lot.	A	B	C	D
R833101	b.	Reading is one of my favorite activities.	A	B	C	D
R833002	c.	Reading is enjoyable.	A	B	C	D
How often do you do each of the following? Fill in one oval on each line.
Response categories
Item			Never or hardly ever	Once or twice a month	Once or twice a week	Almost every day
R833401	a.	Read for fun on your own time	A	B	C	D
R833501	b.	Talk with your friends or family about something you have read	A	B	C	D

Index of Students' Computer Use in Reading

The table below presents the items forming the index of students' computer use in reading at grade 12. This index was designed to measure students' use of computers to complete reading-related activities in school. For each of seven items, students were asked to indicate how often they used a computer to do various reading-related activities in their English/language arts class (never or hardly ever, once or twice a month, once or twice a week, or every day or almost every day).

Items in the index of twelfth-grade students' computer use in reading, grade 12 reading national assessment: 2015
In your English/language arts class this year, how often do you use a computer to do each of the following? Fill in one oval on each line.
Response categories
Item			Never or hardly ever	Once or twice a month	Once or twice a week	Every day or almost every day
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2015 Reading Assessment.
R848301	a.	Learn and practice vocabulary	A	B	C	D
R848309	b.	Write fictional stories	A	B	C	D
R848310	c.	Write informational reports	A	B	C	D
R848304	d.	Produce multimedia reports/projects	A	B	C	D
R848306	e.	Access reading-related websites (for example, websites with book reviews and lists of recommended books)	A	B	C	D
R848307	f.	Conduct research for reading and writing projects	A	B	C	D
R848311	g.	Read books or articles using a digital media device, such as an e-book reader or tablet computer	A	B	C	D

The partial credit IRT model was used to scale the indices. Scaling of the index items was first conducted to get the item parameters and was based on marginal maximum likelihood methodologies. The following tables show the IRT parameters for the 2015 reading indices.

IRT parameters for the index of eighth-grade students' views on reading, grade 8 reading combined national and state assessment, by item: 2015
Item	b_j	d_j1	d_j2	d_j3	d_j4	d_j5
R833001	-0.62	1.65	0.51	-2.15	†	†
R833101	0.30	1.20	-0.21	-0.98	†	†
R833002	-0.32	1.02	0.42	-1.44	†	†
R833401	0.27	0.63	0.07	-0.70	†	†
R833501	0.69	0.86	0.13	-0.99	†	†
† Not applicable. NOTE: The number of d_ji parameters is one less than the number of categories for the item. For items scaled with the partial credit model, parameters a and c are not estimated. The a parameter value is exactly one, and the c parameter is exactly zero. For item j, b_j represents a location parameter related to item difficulty, and d_ji represents the category threshold parameter for category i of item j; d_ji may not sum to zero because of rounding. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2015 Reading Assessment.

IRT parameters for the index of twelfth-grade students' views on reading, grade 12 reading national assessment, by item: 2015
Item	b_j	d_j1	d_j2	d_j3	d_j4	d_j5
R833001	-0.73	1.45	0.53	-1.97	†	†
R833101	0.23	1.22	-0.22	-0.99	†	†
R833002	-0.35	1.02	0.41	-1.43	†	†
R833401	0.46	0.70	-0.04	-0.66	†	†
R833501	0.62	0.94	0.09	-1.02	†	†
† Not applicable. NOTE: The number of d_ji parameters is one less than the number of categories for the item. For items scaled with the partial credit model, parameters a and c are not estimated. The a parameter value is exactly one, and the c parameter is exactly zero. For item j, b_j represents a location parameter related to item difficulty, and d_ji represents the category threshold parameter for category i of item j; d_ji may not sum to zero because of rounding. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2015 Reading Assessment.

IRT parameters for the index of twelfth-grade students' computer use in reading, grade 12 reading national assessment, by item: 2015
Item	b_j	d_j1	d_j2	d_j3	d_j4	d_j5
R848301	0.58	0.27	0.32	-0.59	†	†
R848309	1.28	0.49	0.02	-0.51	†	†
R848310	0.76	1.03	-0.17	-0.87	†	†
R848304	0.95	0.97	-0.23	-0.74	†	†
R848306	0.83	0.58	0.07	-0.65	†	†
R848307	0.48	1.11	-0.21	-0.91	†	†
R848311	0.79	0.22	0.13	-0.35	†	†
† Not applicable. NOTE: The number of d_ji parameters is one less than the number of categories for the item. For items scaled with the partial credit model, parameters a and c are not estimated. The a parameter value is exactly one, and the c parameter is exactly zero. For item j, b_j represents a location parameter related to item difficulty, and d_ji represents the category threshold parameter for category i of item j; d_ji may not sum to zero because of rounding. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2015 Reading Assessment.

After the parameters were estimated, EAP scores were calculated as the estimate of the index score, and transformed to a reporting scale of 0–20.

For each index item, the response categories were scored as numerical values (e.g., the first response category strongly disagree was scored as 1; the second response category disagree was scored as 2).

As a reporting aid, cut points were used to divide the grades 8 and 12 students' views on reading index into low, moderate, and high classifications, and the grade 12 students' computer use in reading index into never, once every few weeks, and once a week or more classifications. The cut points selected to divide the index scores into meaningful categories were based on the distributions of the response average of each index.

As an example, for the index of students' views on reading, grade 8 students were classified as follows:

Students with a response average less than the second response category were classified as low on the index. That is, students who on average responded less than disagree on a question with response options strongly disagree, disagree, agree, and strongly agree generally reported that reading was not one of their favorite activities and that reading was not enjoyable to them, and were classified as low on the index.
Students with a response average greater than or equal to the second response category but less than the third response category were classified as moderate on the index.
Finally, students with a response average greater than or equal to the third response category were classified as high on the index. That is, students who on average responded agree or higher generally reported that reading was one of their favorite activities and that reading was enjoyable to them, and were classified as high on the index.

The tables below show the transformed scale scores and score classifications for the reading indices.

Transformed scores for the index of eighth-grade students' views on reading, grade 8 reading combined national and state assessment, by classification: 2015
Classification	Transformed score	Percentage of students
Low	5.7	2
	6.6	3
	7.3	5
	8.0	7
	8.5	8
Moderate	9.0	9
	9.5	11
	10.0	10
	10.4	10
	10.9	9
High	11.3	7
	11.8	6
	12.3	5
	12.9	4
	13.5	3
	14.3	2
NOTE: Detail may not sum to totals because of rounding. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2015 Reading Assessment.

Transformed scores for the index of twelfth-grade students' views on reading, grade 12 reading national assessment, by classification: 2015
Classification	Transformed score	Percentage of students
Low	5.7	2
	6.6	3
	7.3	5
	7.9	6
	8.5	8
Moderate	9.0	10
	9.5	10
	10.0	11
	10.4	9
	10.9	8
High	11.3	7
	11.8	6
	12.3	5
	12.8	4
	13.5	4
	14.3	2
NOTE: Detail may not sum to totals because of rounding. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2015 Reading Assessment.

Transformed scores for the index of twelfth-grade students' computer use in reading, grade 12 reading national assessment, by classification: 2015
Classification	Transformed score	Percentage of students
Never	7.1	8
	8.1	6
	8.8	10
	9.3	11
	9.8	10
	10.1	9
	10.4	8
Once every few weeks	10.7	8
	10.9	6
	11.2	5
	11.4	4
	11.7	4
	11.9	3
	12.1	2
Once a week or more	12.4	3
	12.6	1
	12.9	1
	13.2	1
	13.5	#
	13.9	#
	14.4	#
	15.1	1
# Rounds to zero. NOTE: Detail may not sum to totals because of rounding. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2015 Reading Assessment.

Last updated 12 June 2025 (SK)

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​​​​​​​​​​NAEP Technical DocumentationDevelopment of the Reading Indices

NAEP Technical DocumentationDevelopment of the Reading Indices