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Version space learning

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257:, i.e., become empty, so that classification becomes impossible. One solution of this problem is proposed by Dubois and Quafafou that proposed the Rough Version Space, where rough sets based approximations are used to learn certain and possible hypothesis in the presence of inconsistent data. 250:" search method that accompanies the version space framework is not a popular learning algorithm, there are some practical implementations that have been developed (e.g., Sverdlik & Reynolds 1992, Hong & Tsang 1997, Dubois & Quafafou 2002). 28: 229:
consistent hypotheses) can be represented by just its lower and upper bounds (maximally general and maximally specific hypothesis sets), and learning operations can be performed just on these representative sets.
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After learning, classification can be performed on unseen examples by testing the hypothesis learned by the algorithm. If the example is consistent with multiple hypotheses, a majority vote rule can be applied.
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data already observed: Thus, if a novel (never-before-seen) data point is observed, it should be assumed to be negative. (I.e., if data has not previously been ruled in, then it's ruled out.)
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data already observed: Thus, if a novel (never-before-seen) data point is observed, it should be assumed to be positive. (I.e., if data has not previously been ruled out, then it's ruled in.)
135: 210:) cover the observed positive training examples, but also cover as much of the remaining feature space without including any negative training examples. These, if enlarged any further, 242:
The notion of version spaces was introduced by Mitchell in the early 1980s as a framework for understanding the basic problem of supervised learning within the context of
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Version space for a "rectangle" hypothesis language in two dimensions. Green pluses are positive examples, and red circles are negative examples. GB is the maximally
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training example, and hence become inconsistent. These maximal hypotheses essentially constitute a (optimistic) claim that the true concept is defined just by the
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training example, and hence become inconsistent. These minimal hypotheses essentially constitute a (pessimistic) claim that the true concept is defined just by the
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A major drawback of version space learning is its inability to deal with noise: any pair of inconsistent examples can cause the version space to
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In settings where there is a generality-ordering on hypotheses, it is possible to represent the version space by two sets of hypotheses: (1) the
144:). A version space learning algorithm is presented with examples, which it will use to restrict its hypothesis space; for each example 327: 47: 394:
Hong, Tzung-Pai; Shian-Shyong Tsang (1997). "A generalized version space learning algorithm for noisy and uncertain data".
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positive hypothesis boundary. The intermediate (thin) rectangles represent the hypotheses in the version space.
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Rough Sets and Current Trends in Computing: Proceedings of the Third International Conference, RSCTC 2002
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Dubois, Vincent; Quafafou, Mohamed (2002). "Concept learning with approximation: Rough version spaces".
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Thus, during learning, the version space (which itself is a set – possibly infinite – containing
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Proceedings, Fourth International Conference on Tools with Artificial Intelligence (TAI '92)
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are removed from the space. This iterative refining of the hypothesis space is called the
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Sverdlik, W.; Reynolds, R.G. (1992). "Dynamic version spaces in machine learning".
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consistent hypotheses, where "consistent" indicates agreement with observed data.
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algorithm, the hypothesis space maintained inside the algorithm, its
26: 58:. Version space learning algorithms search a predefined space of 183:
The most specific hypotheses (i.e., the specific boundary
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The most general hypotheses (i.e., the general boundary
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as possible. These hypotheses, if reduced any further,
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positive hypothesis boundary, and SB is the maximally
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Mitchell, Tom M. (1982). "Generalization as search".
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IEEE Transactions on Knowledge and Data Engineering
129: 322:(2nd ed.). Prentice Hall. pp. 683–686. 130:{\displaystyle H_{1}\lor H_{2}\lor ...\lor H_{n}} 341: 339: 8: 377:. Malvern, Pennsylvania. pp. 239–246. 319:Artificial Intelligence: A Modern Approach 121: 96: 83: 77: 294: 304: 302: 300: 298: 66:. Formally, the hypothesis space is a 7: 176:consistent hypotheses, and (2) the 436:. Arlington, VA. pp. 308–315. 25: 1: 360:10.1016/0004-3702(82)90040-6 272:Inductive logic programming 168:The version space algorithm 467: 148:, the hypotheses that are 423:Mitchell, Tom M. (1997). 383:10.1007/3-540-45813-1_31 348:Artificial Intelligence 267:Formal concept analysis 246:. Although the basic " 427:. Boston: McGraw-Hill. 131: 44:Version space learning 40: 248:candidate elimination 238:Historical background 158:candidate elimination 132: 62:, viewed as a set of 56:binary classification 30: 76: 283:Inductive reasoning 127: 41: 408:10.1109/69.591457 64:logical sentences 16:(Redirected from 458: 451:Machine learning 437: 428: 425:Machine Learning 419: 387: 386: 370: 364: 363: 343: 334: 333: 306: 155: 147: 143: 136: 134: 133: 128: 126: 125: 101: 100: 88: 87: 52:machine learning 21: 466: 465: 461: 460: 459: 457: 456: 455: 441: 440: 431: 422: 393: 390: 372: 371: 367: 345: 344: 337: 330: 310:Russell, Stuart 308: 307: 296: 292: 263: 244:solution search 240: 170: 153: 145: 141: 117: 92: 79: 74: 73: 54:, specifically 23: 22: 15: 12: 11: 5: 464: 462: 454: 453: 443: 442: 439: 438: 429: 420: 402:(2): 336–340. 389: 388: 365: 354:(2): 203–226. 335: 329:978-0137903955 328: 293: 291: 288: 287: 286: 280: 274: 269: 262: 259: 239: 236: 169: 166: 138: 137: 124: 120: 116: 113: 110: 107: 104: 99: 95: 91: 86: 82: 24: 18:Version spaces 14: 13: 10: 9: 6: 4: 3: 2: 463: 452: 449: 448: 446: 435: 430: 426: 421: 417: 413: 409: 405: 401: 397: 392: 391: 384: 380: 376: 369: 366: 361: 357: 353: 349: 342: 340: 336: 331: 325: 321: 320: 315: 314:Norvig, Peter 311: 305: 303: 301: 299: 295: 289: 284: 281: 278: 275: 273: 270: 268: 265: 264: 260: 258: 256: 251: 249: 245: 237: 235: 231: 228: 223: 221: 217: 213: 209: 204: 202: 198: 194: 190: 189:feature space 186: 181: 179: 175: 174:most specific 167: 165: 163: 162:version space 159: 151: 122: 118: 114: 111: 108: 105: 102: 97: 93: 89: 84: 80: 72: 71: 70: 69: 65: 61: 57: 53: 49: 45: 38: 34: 29: 19: 433: 424: 399: 395: 374: 368: 351: 347: 317: 254: 252: 247: 241: 232: 226: 224: 219: 215: 211: 207: 205: 200: 196: 192: 184: 182: 178:most general 177: 173: 171: 161: 157: 150:inconsistent 139: 50:approach to 43: 42: 36: 32: 68:disjunction 290:References 60:hypotheses 316:(2003) . 277:Rough set 115:∨ 103:∨ 90:∨ 445:Category 416:29926783 261:See also 255:collapse 220:negative 216:negative 201:positive 197:positive 37:specific 212:include 193:exclude 48:logical 33:general 414:  326:  412:S2CID 152:with 46:is a 324:ISBN 404:doi 379:doi 356:doi 227:all 447:: 410:. 398:. 352:18 350:. 338:^ 312:; 297:^ 285:. 279:. 214:a 208:GB 195:a 185:SB 164:. 418:. 406:: 400:9 385:. 381:: 362:. 358:: 332:. 154:x 146:x 142:n 123:n 119:H 112:. 109:. 106:. 98:2 94:H 85:1 81:H 20:)

Index

Version spaces

logical
machine learning
binary classification
hypotheses
logical sentences
disjunction
inconsistent
feature space
solution search
Formal concept analysis
Inductive logic programming
Rough set
Inductive reasoning




Russell, Stuart
Norvig, Peter
Artificial Intelligence: A Modern Approach
ISBN
978-0137903955


doi
10.1016/0004-3702(82)90040-6
doi
10.1007/3-540-45813-1_31

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