Magnitude Comparison - 2025

1. Probe description

The Magnitude Comparison probe assesses students’ ability to identify the larger of two numbers.

In 2025 there are two main forms used in the screening:

  • Magnitude Comparison 0-20 (MC0-20) - Foundation
  • Magnitude Comparison 0-100 (MC0-100) - Year 1
Note

This report excludes ABR alternate forms (is_abr == TRUE).

2. Overview of test results

Term Test name Test ID Students Median items attempted Median accuracy (%)* Median correct / min
1 Magnitude Comparison 0-100 MC0-100_2025 2426 16/60 92.9 17.14
1 Magnitude Comparison 0 - 20 MC0-20_2025 2487 16/60 92.6 17.31
3 Magnitude Comparison 0-100 MC0-100_2025 1497 19/60 95.5 22.35
3 Magnitude Comparison 0 - 20 MC0-20_2025 1435 19/60 95.7 22.17
* Accuracy is calculated after removing non-attempted items.

3. Accuracy distribution

4. Response time distribution

Warning: Removed 382 rows containing non-finite outside the scale range
(`stat_boxplot()`).

5. Fluency distribution

Fluency distribution

Term Students 25th percentile Median 75th percentile
Term 1 2426 11.76 17.14 23.75
Term 3 1497 15.60 22.35 28.75

Bottom quartile vs rest

Term Group Students 25th percentile Median 75th percentile
Term 1 Bottom 25% 614 6.43 8.89 10.38
Term 1 Rest 1812 15.92 20.00 26.09
Term 3 Bottom 25% 376 8.57 11.75 13.85
Term 3 Rest 1121 20.82 25.53 31.30

Fluency distribution

Term Students 25th percentile Median 75th percentile
Term 1 2487 11.16 17.31 22.50
Term 3 1435 16.47 22.17 28.16

Bottom quartile vs rest

Term Group Students 25th percentile Median 75th percentile
Term 1 Bottom 25% 623 5.51 7.64 9.64
Term 1 Rest 1864 16.00 20.00 24.49
Term 3 Bottom 25% 365 8.73 12.24 15.00
Term 3 Rest 1070 20.82 24.78 30.46

6. Question type performance

This section shows performance grouped by different question characteristics.

Performance by Ratio

Question type labels:

  • ≥2:1 ratio - The larger number is at least twice the smaller number
  • <2:1 ratio - The larger number is less than twice the smaller number
Correct response time (sec)
Question type Avg items attempted No. response % Correct Median RT 95th RT
Term 1 – Magnitude Comparison 0-100 (MC0-100_2025)
<2:1 ratio 9.9/33 23844 88.1 2 6
≥2:1 ratio 7/27 17002 87.1 2 8
Term 3 – Magnitude Comparison 0-100 (MC0-100_2025)
<2:1 ratio 11.2/33 16743 92.2 2 5
≥2:1 ratio 8.2/27 12203 91.8 2 6
Term 1 – Magnitude Comparison 0 - 20 (MC0-20_2025)
<2:1 ratio 8.7/32 21456 82.3 2 7
≥2:1 ratio 7.6/28 18965 93.9 2 7
Term 3 – Magnitude Comparison 0 - 20 (MC0-20_2025)
<2:1 ratio 10.2/32 14604 89.1 2 5
≥2:1 ratio 9.1/28 13028 96.1 2 6

Performance by Congruence

Question type labels:

  • C (Congruent) - Ones digit in larger number is equal to or larger than ones digit in smaller number
  • I (Incongruent) - Ones digit in larger number is smaller than ones digit in smaller number
Correct response time (sec)
Question type Avg items attempted No. response % Correct Median RT 95th RT
Term 1 – Magnitude Comparison 0-100 (MC0-100_2025)
C 7.7/28 18582 90.1 2 7
I 9.2/32 22264 85.7 2 7
Term 3 – Magnitude Comparison 0-100 (MC0-100_2025)
C 8.8/28 13235 93.7 2 6
I 10.5/32 15711 90.6 2 5
Term 1 – Magnitude Comparison 0 - 20 (MC0-20_2025)
C 10.8/41 26899 86.4 2 8
I 5.5/19 13522 90.3 2 6
Term 3 – Magnitude Comparison 0 - 20 (MC0-20_2025)
C 12.7/41 18222 91.0 2 6
I 6.6/19 9410 95.1 2 4

Performance by Decade

Question type labels:

  • Y (Same decade) - Compared numbers have the same tens digit
  • N (Different decade) - Compared numbers do not have the same tens digit
Correct response time (sec)
Question type Avg items attempted No. response % Correct Median RT 95th RT
Term 1 – Magnitude Comparison 0-100 (MC0-100_2025)
N 15.2/54 36894 87.3 2 7
Y 1.7/6 3952 91.3 2 5
Term 3 – Magnitude Comparison 0-100 (MC0-100_2025)
N 17.5/54 26138 91.9 2 5
Y 1.9/6 2808 93.7 2 5
Term 1 – Magnitude Comparison 0 - 20 (MC0-20_2025)
N 9.5/35 23665 92.3 2 6
Y 6.7/25 16756 81.3 3 9
Term 3 – Magnitude Comparison 0 - 20 (MC0-20_2025)
N 11.3/35 16147 95.8 2 4
Y 8/25 11485 87.7 2 7

7. Item statistics

Download item stats (CSV)

Correct response time (sec)
Question No.  Question No. response % Correct Median RT 95th RT Item discrim.
Term 1
1 68 vs 14 2399 96.5 4.0 14.00 0.05
2 25 vs 52 2401 85.6 2.0 10.00 0.32
3 60 vs 83 2374 71.1 3.0 9.00 0.24
4 82 vs 33 2375 87.2 2.0 7.00 0.34
5 83 vs 92 2360 84.1 2.0 8.00 0.26
6 17 vs 13 2347 94.5 2.0 6.00 0.15
7 99 vs 66 2326 94.2 2.0 5.00 0.18
8 34 vs 62 2272 88.4 3.0 7.00 0.29
9 87 vs 72 2232 91.0 3.0 7.00 0.16
10 15 vs 41 2086 57.7 3.0 8.00 0.37
11 32 vs 10 2077 96.8 2.0 5.00 0.14
12 96 vs 39 1963 93.7 2.0 6.00 0.25
13 20 vs 30 1847 92.7 2.0 4.00 0.25
14 80 vs 19 1701 92.1 2.0 4.00 0.26
15 94 vs 56 1539 85.3 2.0 5.00 0.28
16 8 vs 7 1387 86.7 2.0 5.00 0.18
17 42 vs 92 1209 88.4 2.0 4.00 0.37
18 18 vs 26 1066 91.2 2.0 4.00 0.35
19 43 vs 33 920 87.3 2.0 4.00 0.36
20 26 vs 55 807 92.1 2.0 3.00 0.39
21 15 vs 48 698 93.3 2.0 3.00 0.41
22 38 vs 19 580 93.1 1.0 3.00 0.33
23 46 vs 56 471 90.9 2.0 3.00 0.42
24 39 vs 97 371 89.2 1.0 3.00 0.54
25 90 vs 86 279 84.2 2.0 3.00 0.34
26 55 vs 51 212 86.8 2.0 3.00 0.32
27 22 vs 74 160 90.6 1.0 3.00 0.56
28 89 vs 94 125 76.8 1.0 3.00 0.44
29 31 vs 21 88 81.8 1.0 3.00 0.47
30 51 vs 15 59 84.7 1.0 3.00 0.36
31 30 vs 87 38 81.6 1.0 2.50 0.45
32 44 vs 90 24 83.3 1.0 2.10 0.75
33 46 vs 76 15 80.0 1.0 2.45 NA
34 64 vs 25 8 87.5 1.0 2.00 NA
35 79 vs 83 6 50.0 1.0 3.70 NA
36 62 vs 67 5 60.0 2.0 3.80 NA
37 27 vs 58 4 50.0 3.0 3.90 NA
38 16 vs 9 3 100.0 1.0 2.80 NA
39 68 vs 70 2 50.0 2.0 2.00 NA
40 23 vs 82 1 100.0 2.0 2.00 NA
41 71 vs 21 1 100.0 2.0 2.00 NA
42 45 vs 8 1 100.0 2.0 2.00 NA
43 23 vs 33 1 100.0 2.0 2.00 NA
44 93 vs 28 1 100.0 2.0 2.00 NA
45 37 vs 42 1 100.0 3.0 3.00 NA
46 98 vs 91 1 100.0 3.0 3.00 NA
47 38 vs 13 1 100.0 3.0 3.00 NA
48 67 vs 82 1 100.0 2.0 2.00 NA
49 30 vs 40 1 100.0 3.0 3.00 NA
Term 3
1 68 vs 14 1476 98.9 3.0 14.00 0.13
2 25 vs 52 1484 92.0 2.0 7.00 0.36
3 60 vs 83 1454 80.4 2.0 7.00 0.24
4 82 vs 33 1476 92.8 2.0 6.00 0.32
5 83 vs 92 1474 89.6 2.0 6.00 0.26
6 17 vs 13 1469 95.7 2.0 5.00 0.18
7 99 vs 66 1464 96.7 2.0 4.00 0.16
8 34 vs 62 1436 93.7 2.0 5.75 0.32
9 87 vs 72 1419 93.4 2.0 6.00 0.20
10 15 vs 41 1368 65.6 3.0 6.15 0.36
11 32 vs 10 1375 97.4 2.0 4.10 0.18
12 96 vs 39 1337 95.6 2.0 5.00 0.24
13 20 vs 30 1288 94.6 2.0 4.00 0.28
14 80 vs 19 1255 96.2 2.0 4.00 0.23
15 94 vs 56 1178 90.4 2.0 5.00 0.18
16 8 vs 7 1094 91.0 2.0 5.00 0.16
17 42 vs 92 1007 93.2 2.0 4.00 0.29
18 18 vs 26 937 94.9 2.0 4.00 0.26
19 43 vs 33 854 92.6 2.0 4.00 0.34
20 26 vs 55 757 96.4 2.0 3.00 0.33
21 15 vs 48 664 96.8 2.0 3.00 0.35
22 38 vs 19 589 95.2 1.0 3.00 0.33
23 46 vs 56 487 95.3 2.0 3.00 0.40
24 39 vs 97 403 92.1 2.0 3.00 0.28
25 90 vs 86 326 88.3 2.0 3.00 0.24
26 55 vs 51 241 93.4 2.0 3.00 0.28
27 22 vs 74 188 95.2 1.0 2.00 0.46
28 89 vs 94 137 80.3 2.0 3.00 0.35
29 31 vs 21 96 89.6 1.0 3.00 0.27
30 51 vs 15 63 88.9 1.0 2.00 0.60
31 30 vs 87 40 92.5 1.0 2.00 0.61
32 44 vs 90 34 91.2 1.0 2.00 0.52
33 46 vs 76 30 93.3 1.0 2.00 0.49
34 64 vs 25 20 80.0 1.0 3.25 0.37
35 79 vs 83 12 50.0 1.5 2.75 NA
36 62 vs 67 4 100.0 1.5 2.00 NA
37 27 vs 58 4 100.0 1.0 1.00 NA
38 16 vs 9 4 75.0 1.0 1.00 NA
39 68 vs 70 2 100.0 1.5 1.95 NA
Correct response time (sec)
Question No.  Question No. response % Correct Median RT 95th RT Item discrim.
Term 1
1 3 vs 6 2440 95.4 4.0 16.00 0.20
2 14 vs 2 2442 95.4 3.0 8.00 0.21
3 12 vs 9 2441 87.5 3.0 8.00 0.22
4 5 vs 17 2413 94.3 2.0 6.00 0.27
5 19 vs 10 2417 78.8 3.0 9.00 0.28
6 7 vs 10 2388 89.3 2.0 6.00 0.25
7 17 vs 13 2332 69.8 3.0 10.00 0.21
8 19 vs 18 2272 59.4 3.0 8.00 0.17
9 5 vs 13 2201 91.6 2.0 5.00 0.29
10 20 vs 11 2120 87.1 2.0 6.00 0.26
11 8 vs 4 2023 89.9 3.0 6.00 0.20
12 5 vs 16 1940 94.9 2.0 4.00 0.28
13 17 vs 9 1830 93.9 2.0 4.00 0.27
14 3 vs 14 1718 95.6 2.0 4.00 0.25
15 11 vs 15 1580 89.9 2.0 4.00 0.24
16 8 vs 5 1368 90.3 2.0 4.00 0.26
17 4 vs 14 1266 95.1 2.0 4.00 0.34
18 8 vs 7 1081 83.9 2.0 5.00 0.38
19 5 vs 20 875 96.2 2.0 3.00 0.33
20 10 vs 18 733 85.3 2.0 4.00 0.22
21 10 vs 5 596 91.6 2.0 3.00 0.45
22 1 vs 10 491 94.7 1.0 3.00 0.37
23 11 vs 7 386 87.6 2.0 3.00 0.48
24 18 vs 6 303 89.4 1.0 2.00 0.49
25 15 vs 19 212 83.5 2.0 3.00 0.26
26 3 vs 5 144 88.9 2.0 3.65 0.42
27 5 vs 12 108 92.6 1.0 2.05 0.39
28 13 vs 11 74 74.3 1.0 2.00 0.32
29 8 vs 17 56 89.3 1.0 2.00 0.52
30 19 vs 13 39 64.1 1.0 2.00 0.39
31 3 vs 7 28 78.6 1.0 2.95 0.59
32 6 vs 18 23 91.3 1.0 2.00 0.38
33 9 vs 15 15 93.3 1.0 2.00 NA
34 17 vs 2 15 93.3 1.0 1.35 NA
35 3 vs 16 11 90.9 1.0 2.00 NA
36 10 vs 6 7 85.7 1.0 1.75 NA
37 2 vs 15 7 100.0 1.0 1.00 NA
38 12 vs 14 5 100.0 1.0 1.00 NA
39 16 vs 9 4 100.0 1.0 1.00 NA
40 17 vs 12 4 50.0 1.0 1.00 NA
41 4 vs 9 4 100.0 1.5 3.70 NA
42 19 vs 2 4 100.0 1.0 1.85 NA
43 8 vs 13 4 100.0 1.0 1.85 NA
44 20 vs 10 1 100.0 1.0 1.00 NA
Term 3
1 3 vs 6 1407 96.7 4.0 14.00 0.23
2 14 vs 2 1417 96.1 2.0 6.00 0.26
3 12 vs 9 1416 92.1 2.0 6.00 0.26
4 5 vs 17 1409 95.7 2.0 5.00 0.31
5 19 vs 10 1407 86.1 2.0 7.00 0.25
6 7 vs 10 1402 94.2 2.0 5.00 0.33
7 17 vs 13 1395 84.8 2.0 7.00 0.25
8 19 vs 18 1378 69.7 3.0 8.00 0.17
9 5 vs 13 1366 95.7 2.0 5.00 0.29
10 20 vs 11 1345 94.1 2.0 5.00 0.29
11 8 vs 4 1314 91.6 2.0 5.00 0.22
12 5 vs 16 1279 96.7 2.0 4.00 0.33
13 17 vs 9 1257 96.3 2.0 4.00 0.34
14 3 vs 14 1208 97.6 2.0 3.00 0.34
15 11 vs 15 1160 93.2 2.0 4.00 0.18
16 8 vs 5 1087 91.7 2.0 4.00 0.25
17 4 vs 14 1014 97.5 2.0 3.00 0.35
18 8 vs 7 911 91.0 2.0 5.00 0.28
19 5 vs 20 816 98.0 1.0 3.00 0.37
20 10 vs 18 717 83.8 2.0 4.00 0.14
21 10 vs 5 593 96.3 2.0 3.00 0.32
22 1 vs 10 508 97.4 1.0 3.00 0.46
23 11 vs 7 441 96.1 2.0 3.00 0.30
24 18 vs 6 361 96.1 1.0 2.00 0.45
25 15 vs 19 279 90.3 2.0 3.00 0.46
26 3 vs 5 210 91.4 2.0 3.00 0.25
27 5 vs 12 158 94.9 1.0 2.00 0.65
28 13 vs 11 116 90.5 1.0 2.00 0.21
29 8 vs 17 88 96.6 1.0 2.00 0.61
30 19 vs 13 61 91.8 1.0 3.00 0.17
31 3 vs 7 41 92.7 1.5 3.00 0.31
32 6 vs 18 25 96.0 1.0 2.00 0.77
33 9 vs 15 13 84.6 1.0 2.00 NA
34 17 vs 2 11 90.9 1.0 1.55 NA
35 3 vs 16 9 100.0 1.0 1.00 NA
36 10 vs 6 7 85.7 1.0 1.00 NA
37 2 vs 15 4 100.0 1.0 1.00 NA
38 12 vs 14 2 50.0 1.0 1.00 NA

8. Item correct response time

Term 1

Term 3

Term 1

Term 3