Appendix Part 1. 131

Appendix Part 1. Classification Tables for 

Logistic Regression Equations for Irrigation

Tables

A1–1. Classification table of probability levels for the logistic-regression equation for 

estimating the probability of turf-farm irrigation on a specific day in the Pawcatuck 

River Basin, southwestern Rhode Island and southeastern Connecticut, 2000–04 ......132

A1–2. Classification table of probability levels for the logistic-regression equation for 

estimating the probability of golf-course irrigation with surface-water withdrawals 

on a specific day in the Pawcatuck River Basin, southwestern Rhode Island and 

southeastern Connecticut, 2000–04.......................................................................................134

A1–3. Classification table of probability levels for the logistic-regression equation for 

estimating the probability of golf-course irrigation with groundwater withdrawals 

on a specific day in the Pawcatuck River Basin, southwestern Rhode Island and 

southeastern Connecticut.......................................................................................................136
132 Appendix Part 1.

Table A1–1. Classification table of probability levels for the logistic-regression equation for estimating the probability of turf-farm 

irrigation on a specific day in the Pawcatuck River Basin, southwestern Rhode Island and southeastern Connecticut, 2000–04.

—Continued

[Correct: The frequency with which days of irrigation are correctly classified. Incorrect: The frequency with which days of irrigation are incorrectly classified. Event: A day of irrigation. Nonevent: A day of no irrigation. Percentages: Correct: The probability that the equation correctly classifies the sample data 

for each probability cutpoint. Sensitivity: The ratio of correctly classified events to the total number of events. Specificity: The ratio of correctly classified 

nonevents to the total number of nonevents. False positive: The ratio of the number of nonevents incorrectly classified as events to the sum of all observations classified as events. False negative: The ratio of the number of events incorrectly classified as nonevents to the sum of all observations classified as 

nonevents. SAS Institute, Inc., 1995, p. 45–50. Note: Shaded row highlights the cutpoint probability chosen for this equation and the associated classification 

table information as discussed in Part 1 of this report. --, not applicable]

Probability 

level 

(cutpoint)

Correct Incorrect Percentages

Event Nonevent Event Nonevent Correct Sensitivity Specificity False positive False negative

0.00 373 0 547 0 40.5 100.0 0.0 59.5 --

0.02 371 45 502 2 45.2 99.5 8.2 57.5 4.3

0.04 364 81 466 9 48.4 97.6 14.8 56.1 10.0

0.06 363 122 425 10 52.7 97.3 22.3 53.9 7.6

0.08 361 143 404 12 54.8 96.8 26.1 52.8 7.7

0.10 354 163 384 19 56.2 94.9 29.8 52.0 10.4

0.12 351 189 358 22 58.7 94.1 34.6 50.5 10.4

0.14 349 216 331 24 61.4 93.6 39.5 48.7 10.0

0.16 348 240 307 25 63.9 93.3 43.9 46.9 9.4

0.18 342 261 286 31 65.5 91.7 47.7 45.5 10.6

0.20 340 286 261 33 68.0 91.2 52.3 43.4 10.3

0.22 333 308 239 40 69.7 89.3 56.3 41.8 11.5

0.24 326 319 228 47 70.1 87.4 58.3 41.2 12.8

0.26 322 342 205 51 72.2 86.3 62.5 38.9 13.0

0.28 321 365 182 52 74.6 86.1 66.7 36.2 12.5

0.30 315 382 165 58 75.8 84.5 69.8 34.4 13.2

0.32 307 394 153 66 76.2 82.3 72.0 33.3 14.3

0.34 302 406 141 71 77.0 81.0 74.2 31.8 14.9

0.36 300 412 135 73 77.4 80.4 75.3 31.0 15.1

0.38 294 421 126 79 77.7 78.8 77.0 30.0 15.8

0.40 289 427 120 84 77.8 77.5 78.1 29.3 16.4

0.42 288 440 107 85 79.1 77.2 80.4 27.1 16.2

0.44 283 453 94 90 80.0 75.9 82.8 24.9 16.6

0.46 279 462 85 94 80.5 74.8 84.5 23.4 16.9

0.48 278 466 81 95 80.9 74.5 85.2 22.6 16.9

0.50 273 470 77 100 80.8 73.2 85.9 22.0 17.5

0.52 264 474 73 109 80.2 70.8 86.7 21.7 18.7

0.54 258 482 65 115 80.4 69.2 88.1 20.1 19.3

0.56 249 490 57 124 80.3 66.8 89.6 18.6 20.2

0.58 239 493 54 134 79.6 64.1 90.1 18.4 21.4

0.60 231 495 52 142 78.9 61.9 90.5 18.4 22.3

0.62 224 503 44 149 79.0 60.1 92.0 16.4 22.9

0.64 213 506 41 160 78.2 57.1 92.5 16.1 24.0

0.66 206 513 34 167 78.2 55.2 93.8 14.2 24.6

0.68 199 515 32 174 77.6 53.4 94.1 13.9 25.3
Table A1–1 133

Table A1–1. Classification table of probability levels for the logistic-regression equation for estimating the probability of turf-farm 

irrigation on a specific day in the Pawcatuck River Basin, southwestern Rhode Island and southeastern Connecticut, 2000–04.

—Continued

[Correct: The frequency with which days of irrigation are correctly classified. Incorrect: The frequency with which days of irrigation are incorrectly classified. Event: A day of irrigation. Nonevent: A day of no irrigation. Percentages: Correct: The probability that the equation correctly classifies the sample data 

for each probability cutpoint. Sensitivity: The ratio of correctly classified events to the total number of events. Specificity: The ratio of correctly classified 

nonevents to the total number of nonevents. False positive: The ratio of the number of nonevents incorrectly classified as events to the sum of all observations classified as events. False negative: The ratio of the number of events incorrectly classified as nonevents to the sum of all observations classified as 

nonevents. SAS Institute, Inc., 1995, p. 45–50. Note: Shaded row highlights the cutpoint probability chosen for this equation and the associated classification 

table information as discussed in Part 1 of this report. --, not applicable]

Probability 

level 

(cutpoint)

Correct Incorrect Percentages

Event Nonevent Event Nonevent Correct Sensitivity Specificity False positive False negative

0.70 189 520 27 184 77.1 50.7 95.1 12.5 26.1

0.72 182 526 21 191 77.0 48.8 96.2 10.3 26.6

0.74 174 531 16 199 76.6 46.6 97.1 8.4 27.3

0.76 163 534 13 210 75.8 43.7 97.6 7.4 28.2

0.78 154 536 11 219 75.0 41.3 98.0 6.7 29.0

0.80 145 537 10 228 74.1 38.9 98.2 6.5 29.8

0.82 126 538 9 247 72.2 33.8 98.4 6.7 31.5

0.84 111 538 9 262 70.5 29.8 98.4 7.5 32.8

0.86 95 542 5 278 69.2 25.5 99.1 5.0 33.9

0.88 83 545 2 290 68.3 22.3 99.6 2.4 34.7

0.90 68 547 0 305 66.8 18.2 100.0 0.0 35.8

0.92 55 547 0 318 65.4 14.7 100.0 0.0 36.8

0.94 41 547 0 332 63.9 11.0 100.0 0.0 37.8

0.96 15 547 0 358 61.1 4.0 100.0 0.0 39.6

0.98 2 547 0 371 59.7 0.5 100.0 0.0 40.4

1.00 0 547 0 373 59.5 0.0 100.0 0.0 40.5
134 Appendix Part 1.

Table A1–2. Classification table of probability levels for the logistic-regression equation for estimating the probability of golfcourse irrigation with surface-water withdrawals on a specific day in the Pawcatuck River Basin, southwestern Rhode Island and 

southeastern Connecticut, 2000–04.—Continued

[Correct: The frequency with which days of irrigation are correctly classified. Incorrect: The frequency with which days of irrigation are incorrectly classified. Event: A day of irrigation. Nonevent: A day of no irrigation. Percentages: Correct: The probability that the equation correctly classifies the sample data 

for each probability cutpoint. Sensitivity: The ratio of correctly classified events to the total number of events. Specificity: The ratio of correctly classified 

nonevents to the total number of nonevents. False positive: The ratio of the number of nonevents incorrectly classified as events to the sum of all observations 

classified as events. False negative: The ratio of the number of events incorrectly classified as nonevents to the sum of all observations classified as nonevents. 

SAS Institute, Inc., 1995, p. 45–50. Note: Shaded row highlights the cutpoint probability chosen for this equation and the associated classification table information as discussed in Part 1 of this report. --, not applicable]

Probability 

level 

(cutpoint)

Correct Incorrect Percentages

Event Nonevent Event Nonevent Correct Sensitivity Specificity False positive False negative

0.00 374 0 701 0 34.8 100.0 0.0 65.2 --

0.02 369 98 603 5 43.4 98.7 14.0 62.0 4.9

0.04 366 159 542 8 48.8 97.9 22.7 59.7 4.8

0.06 363 204 497 11 52.7 97.1 29.1 57.8 5.1

0.08 363 238 463 11 55.9 97.1 34.0 56.1 4.4

0.10 361 269 432 13 58.6 96.5 38.4 54.5 4.6

0.12 359 297 404 15 61.0 96.0 42.4 52.9 4.8

0.14 357 332 369 17 64.1 95.5 47.4 50.8 4.9

0.16 354 366 335 20 67.0 94.7 52.2 48.6 5.2

0.18 350 389 312 24 68.7 93.6 55.5 47.1 5.8

0.20 349 418 283 25 71.3 93.3 59.6 44.8 5.6

0.22 343 442 259 31 73.0 91.7 63.1 43.0 6.6

0.24 337 461 240 37 74.2 90.1 65.8 41.6 7.4

0.26 327 482 219 47 75.3 87.4 68.8 40.1 8.9

0.28 319 506 195 55 76.7 85.3 72.2 37.9 9.8

0.30 307 515 186 67 76.5 82.1 73.5 37.7 11.5

0.32 305 529 172 69 77.6 81.6 75.5 36.1 11.5

0.34 297 544 157 77 78.2 79.4 77.6 34.6 12.4

0.36 294 555 146 80 79.0 78.6 79.2 33.2 12.6

0.38 284 566 135 90 79.1 75.9 80.7 32.2 13.7

0.40 280 572 129 94 79.3 74.9 81.6 31.5 14.1

0.42 265 580 121 109 78.6 70.9 82.7 31.3 15.8

0.44 260 588 113 114 78.9 69.5 83.9 30.3 16.2

0.46 252 592 109 122 78.5 67.4 84.5 30.2 17.1

0.48 244 598 103 130 78.3 65.2 85.3 29.7 17.9

0.50 240 600 101 134 78.1 64.2 85.6 29.6 18.3

0.52 232 608 93 142 78.1 62.0 86.7 28.6 18.9

0.54 225 614 87 149 78.0 60.2 87.6 27.9 19.5

0.56 220 619 82 154 78.0 58.8 88.3 27.2 19.9

0.58 211 626 75 163 77.9 56.4 89.3 26.2 20.7

0.60 204 630 71 170 77.6 54.5 89.9 25.8 21.3

0.62 192 639 62 182 77.3 51.3 91.2 24.4 22.2

0.64 178 648 53 196 76.8 47.6 92.4 22.9 23.2

0.66 169 652 49 205 76.4 45.2 93.0 22.5 23.9

0.68 160 657 44 214 76.0 42.8 93.7 21.6 24.6
Table A1–2 135

Table A1–2. Classification table of probability levels for the logistic-regression equation for estimating the probability of golfcourse irrigation with surface-water withdrawals on a specific day in the Pawcatuck River Basin, southwestern Rhode Island and 

southeastern Connecticut, 2000–04.—Continued

[Correct: The frequency with which days of irrigation are correctly classified. Incorrect: The frequency with which days of irrigation are incorrectly classified. Event: A day of irrigation. Nonevent: A day of no irrigation. Percentages: Correct: The probability that the equation correctly classifies the sample data 

for each probability cutpoint. Sensitivity: The ratio of correctly classified events to the total number of events. Specificity: The ratio of correctly classified 

nonevents to the total number of nonevents. False positive: The ratio of the number of nonevents incorrectly classified as events to the sum of all observations 

classified as events. False negative: The ratio of the number of events incorrectly classified as nonevents to the sum of all observations classified as nonevents. 

SAS Institute, Inc., 1995, p. 45–50. Note: Shaded row highlights the cutpoint probability chosen for this equation and the associated classification table information as discussed in Part 1 of this report. --, not applicable]

Probability 

level 

(cutpoint)

Correct Incorrect Percentages

Event Nonevent Event Nonevent Correct Sensitivity Specificity False positive False negative

0.70 149 665 36 225 75.7 39.8 94.9 19.5 25.3

0.72 143 670 31 231 75.6 38.2 95.6 17.8 25.6

0.74 134 673 28 240 75.1 35.8 96.0 17.3 26.3

0.76 116 678 23 258 73.9 31.0 96.7 16.5 27.6

0.78 102 684 17 272 73.1 27.3 97.6 14.3 28.5

0.80 91 689 12 283 72.6 24.3 98.3 11.7 29.1

0.82 75 692 9 299 71.3 20.1 98.7 10.7 30.2

0.84 68 694 7 306 70.9 18.2 99.0 9.3 30.6

0.86 57 699 2 317 70.3 15.2 99.7 3.4 31.2

0.88 47 701 0 327 69.6 12.6 100.0 0.0 31.8

0.90 30 701 0 344 68.0 8.0 100.0 0.0 32.9

0.92 16 701 0 358 66.7 4.3 100.0 0.0 33.8

0.94 5 701 0 369 65.7 1.3 100.0 0.0 34.5

0.96 2 701 0 372 65.4 0.5 100.0 0.0 34.7

0.98 0 701 0 374 65.2 0.0 100.0 0.0 34.8
136 Appendix Part 1.

Table A1–3. Classification table of probability levels for the logistic-regression equation for estimating the probability of golf-course 

irrigation with groundwater withdrawals on a specific day in the Pawcatuck River Basin, southwestern Rhode Island and southeastern 

Connecticut.—Continued

[Correct: The frequency with which days of irrigation are correctly classified. Incorrect: The frequency with which days of irrigation are incorrectly classified. Event: A day of irrigation. Nonevent: A day of no irrigation. Percentages: Correct: The probability that the equation correctly classifies the sample data 

for each probability cutpoint. Sensitivity: The ratio of correctly classified events to the total number of events. Specificity: The ratio of correctly classified 

nonevents to the total number of nonevents. False positive: The ratio of the number of nonevents incorrectly classified as events to the sum of all observations 

classified as events. False negative: The ratio of the number of events incorrectly classified as nonevents to the sum of all observations classified as nonevents. 

SAS Institute, Inc., 1995, p. 45–50. Note: Shaded row highlights the cutpoint probability chosen for this equation and the associated classification table information as discussed in Part 1 of this report. --, not applicable]

Probability 

level 

(cutpoint)

Correct Incorrect Percentages

Event Nonevent Event Nonevent Correct Sensitivity Specificity False positive False negative

0.10 472 0 96 0 83.1 100.0 0.0 16.9 --

0.12 471 1 95 1 83.1 99.8 1.0 16.8 50.0

0.14 471 4 92 1 83.6 99.8 4.2 16.3 20.0

0.16 471 5 91 1 83.8 99.8 5.2 16.2 16.7

0.18 471 5 91 1 83.8 99.8 5.2 16.2 16.7

0.20 471 5 91 1 83.8 99.8 5.2 16.2 16.7

0.24 471 7 89 1 84.2 99.8 7.3 15.9 12.5

0.26 471 9 87 1 84.5 99.8 9.4 15.6 10.0

0.28 471 9 87 1 84.5 99.8 9.4 15.6 10.0

0.30 470 9 87 2 84.3 99.6 9.4 15.6 18.2

0.32 470 13 83 2 85.0 99.6 13.5 15.0 13.3

0.34 468 17 79 4 85.4 99.2 17.7 14.4 19.0

0.36 468 22 74 4 86.3 99.2 22.9 13.7 15.4

0.38 463 25 71 9 85.9 98.1 26.0 13.3 26.5

0.40 463 27 69 9 86.3 98.1 28.1 13.0 25.0

0.42 462 27 69 10 86.1 97.9 28.1 13.0 27.0

0.44 458 29 67 14 85.7 97.0 30.2 12.8 32.6

0.46 456 32 64 16 85.9 96.6 33.3 12.3 33.3

0.48 455 38 58 17 86.8 96.4 39.6 11.3 30.9

0.50 451 43 53 21 87.0 95.6 44.8 10.5 32.8

0.52 448 46 50 24 87.0 94.9 47.9 10.0 34.3

0.54 441 50 46 31 86.4 93.4 52.1 9.4 38.3

0.56 437 53 43 35 86.3 92.6 55.2 9.0 39.8

0.58 431 56 40 41 85.7 91.3 58.3 8.5 42.3

0.60 421 58 38 51 84.3 89.2 60.4 8.3 46.8

0.62 417 60 36 55 84.0 88.3 62.5 7.9 47.8

0.64 410 64 32 62 83.5 86.9 66.7 7.2 49.2

0.66 407 68 28 65 83.6 86.2 70.8 6.4 48.9

0.68 404 71 25 68 83.6 85.6 74.0 5.8 48.9

0.70 402 74 22 70 83.8 85.2 77.1 5.2 48.6

0.72 400 74 22 72 83.5 84.7 77.1 5.2 49.3

0.74 399 75 21 73 83.5 84.5 78.1 5.0 49.3

0.76 396 75 21 76 82.9 83.9 78.1 5.0 50.3

0.78 389 76 20 83 81.9 82.4 79.2 4.9 52.2

0.80 378 76 20 94 79.9 80.1 79.2 5.0 55.3
Table A1–3 137

Table A1–3. Classification table of probability levels for the logistic-regression equation for estimating the probability of golf-course 

irrigation with groundwater withdrawals on a specific day in the Pawcatuck River Basin, southwestern Rhode Island and southeastern 

Connecticut.—Continued

[Correct: The frequency with which days of irrigation are correctly classified. Incorrect: The frequency with which days of irrigation are incorrectly classified. Event: A day of irrigation. Nonevent: A day of no irrigation. Percentages: Correct: The probability that the equation correctly classifies the sample data 

for each probability cutpoint. Sensitivity: The ratio of correctly classified events to the total number of events. Specificity: The ratio of correctly classified 

nonevents to the total number of nonevents. False positive: The ratio of the number of nonevents incorrectly classified as events to the sum of all observations 

classified as events. False negative: The ratio of the number of events incorrectly classified as nonevents to the sum of all observations classified as nonevents. 

SAS Institute, Inc., 1995, p. 45–50. Note: Shaded row highlights the cutpoint probability chosen for this equation and the associated classification table information as discussed in Part 1 of this report. --, not applicable]

Probability 

level 

(cutpoint)

Correct Incorrect Percentages

Event Nonevent Event Nonevent Correct Sensitivity Specificity False positive False negative

0.82 370 77 19 102 78.7 78.4 80.2 4.9 57.0

0.84 367 78 18 105 78.3 77.8 81.3 4.7 57.4

0.86 358 82 14 114 77.5 75.8 85.4 3.8 58.2

0.88 343 84 12 129 75.2 72.7 87.5 3.4 60.6

0.90 326 85 11 146 72.4 69.1 88.5 3.3 63.2

0.92 304 89 7 168 69.2 64.4 92.7 2.3 65.4

0.94 279 90 6 193 65.0 59.1 93.8 2.1 68.2

0.96 247 92 4 225 59.7 52.3 95.8 1.6 71.0

0.98 187 94 2 285 49.5 39.6 97.9 1.1 75.2

1.00 0 96 0 472 16.9 0.0 100.0 -- 83.1
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