NAEP Technical DocumentationOverall Descriptive Statistics for Item Blocks as Defined After Scaling, Grade 4 Reading Combined National and State Assessment, by Block and Item Type: 2017

Overall descriptive statistics for item blocks as defined after scaling, grade 4 reading combined national and state assessment, by block and item type: 2017
Statistic	Item type	Block R1	Block R2	Block R3	Block R4	Block R5	Block R6	Block R7	Block R8	Block R9	Block R10
Number of scaled items	Total	11	8	10	10	10	10	10	10	9	8
	Multiple choice	8	5	7	7	6	7	7	6	5	6
	Dichotomously scored constructed-response	1	1	0	0	1	0	1	0	1	1
	Polytomously scored constructed-response	2	2	3	3	3	3	2	4	3	1
Unweighted sample size	†	29,300	29,800	29,100	29,100	29,100	29,300	29,600	29,300	29,100	29,100
Weighted average item score¹	†	.65	.59	.53	.53	.44	.46	.51	.47	.48	.52
Weighted average polyserial	†	.68	.70	.73	.71	.68	.66	.64	.70	.64	.67
Weighted alpha reliability	†	.77	.71	.79	.76	.76	.75	.72	.78	.70	.63
Weighted proportion of students attempting last item²	†	.91	.87	.86	.89	.88	.85	.85	.84	.87	.93
† Not applicable. ¹ The "Weighted average item score" of polytomous items is standardized to have a scale of 0 to 1 so they are comparable to dichotomously scored items. ² The "Weighted proportion of students attempting last item" is equal to 1 – (Percent not responding to last item / 100). NOTE: Item statistics in this table are described on the page Blocks of Items. SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2017 Reading Assessment.

Last updated 11 May 2022 (SK)