Students' Understanding of Bar Graphs and Histograms: Results From the LOCUS Assessments

Figures & data

Table 1. The number of students taking each level of the LOCUS assessments during the pilot and operational administrations.

Forms	Pilot	Operational
Beginning/Intermediate Forms in Grades 6–8	2013	1762
Beginning/Intermediate Forms in Grades 9–12	62	162
Intermediate/Advanced Forms in Grades 6–8	0	0
Intermediate/Advanced Forms in Grades 9–12	1249	1491
Females	46%	45%
Males	51%	51%

NOTE: The percent of female and male students during each administration is also given. Percentages do not sum to 100% because some students did not answer the question.

Table 2. Summaries of what graphs were used and from which student's data were collected.

Item code	Data collected from students in	Total N	Graphs in item
Item 1	Grades 9–12	309	Histogram and case-value bar graphs
Item 2	Grades 9–12	308	Distributional bar graph
Item 3	Grades 9–12	312	Histograms
Item 3R	Grades 6–8	1881	Histograms
Item 3R	Grades 9–12	1465	Histograms
Item 4	Grades 9–12	306	Histograms
Item 5	Grades 9–12	315	Histograms
Item CR1	Grades 6–8	947	Distributional bar graphs
Item CR2	Grades 9–12	720	Histograms

short-legendFigure 1.

Figure 2. The full text of Item 2. This item assesses the collect data step at GAISE Level B and CCSSM 6.SP.4 and S-ID.1.

Figure 3. The full text of Item 3. This item assesses the analyze data step at GAISE Level B and CCSSM 6.SP.5c and S-ID.3.

Figure 4. The full text of Item 4. This item assesses the analyze data step at GAISE Level B and CCSSM 6.SP.5c and S-ID.3.

Figure 5. The full text of Item 5. This item assesses the analyze data step at GAISE Level B and CCSSM 6.SP.5c and S-ID.2.

Figure 6. The full text of Item CR1. This item appeared on the Beginning/Intermediate version of the assessment and assesses CCSSM 1.MD.4, 3.MD.10, and S-ID.3.

Figure 7. The full text of Item CR2. This item appeared on the Intermediate/Advanced version of the assessment and assesses CCSSM 7.SP.3, 7.SP.4, S-ID.2, S-ID.3, and S-IC.3.

Table 3. For each item, the percentage of students that chose each response and the total number of students responding to the question.

Item code	Form	% A	% B	% C	% D	Total N
Item 1	Intermediate/Advanced	28.66	20.70	1.27	47.77	309
Item 2	Intermediate/Advanced	12.82	28.85	16.99	40.06	308
Item 3	Intermediate/Advanced	46.50	33.12	7.96	11.78	312
Item 4	Intermediate/Advanced	4.25	31.05	46.08	18.63	306
Item 5	Intermediate/Advanced	19.56	53.00	16.09	10.73	315
Item 3R	Beginning/Intermediate	43.89	17.43	15.42	20.27	1881
Item 3R	Intermediate/Advanced	39.10	29.11	11.33	18.71	1465

NOTE: The correct answer is indicated by bold italics. Percentages do not sum to 100% because some students did not answer the question. Items in the top half of the table appeared on the pilot administration; items in the bottom half appeared on the operational administration.

Table 4. Percentage of students receiving each score for the constructed-response items.

	Percent receiving each score
Item code	0	1	2	3	4	Total N
Item CR1	25.82	15.70	50.37	4.11	3.79	947
Item CR2	50.27	18.41	25.14	1.92	3.16	720

NOTE: Percentages do not sum to 100% because some students did not answer the question. Responses were scored holistically with a minimum score of 0 and a maximum score of 4.

Figure 8. Example correct student responses to part (c) of Item CR1.

Figure 9. Example incorrect student responses to part (c) of Item CR1.

Figure 10. Example correct student responses to part (a) of Item CR2.

Figure 11. Example incorrect student responses to part (a) of Item CR2.