Table 1 Preference Index calculations.

From: A history-based method to estimate animal preference

Test Number (tn) STEP 1 STEP 2 STEP 3 STEP 4 STEP 5 STEP 6 STEP 7
Raw Frequency (RF) 1 Cumulative frequency 2 Area 3 Cumulative area 4 Expected Area 5 (ExA) Variation of cumulative area from the ExA 6 Preference Index (PI) 7
1 9 9 4.5 4.5 12.4 −7.9 −7.9
2 57 66 85.5 90.0 55.5 34.5 26.6
3 28 94 70.0 160.0 113.6 46.4 73.0
4 56 150 196.0 356.0 208.1 147.9 220.9
5 72 222 324.0 680.0 326.3 353.8 574.6
6 59 281 324.5 1004.5 451.4 553.1 1127.8
7 77 358 500.5 1505.0 607.4 897.6 2025.4
8 79 437 592.5 2097.5 785.5 1312.0 3337.4
9 99 536 841.5 2939.0 1023.5 1915.5 5252.9
10 99 635 940.5 3879.5 1301.4 2578.1 7831.0
  1. This procedure is carried out for each colour. Example extracted from fish 1, yellow colour.
  2. 1Frequencies obtained in each test.
  3. 2.
  4. 3Areas calculated as shown in Fig. 2.
  5. 4.
  6. 5Mean of cumulative areas from each colour in the respective test number and fish. In this table, we show data only for the yellow colour; the ExA is calculated from data of all tested colours at tn for fish 1.
  7. 6Data from Step 4–Step 5.
  8. 7Cumulative data of Step 6.