Table of Contents

Training File Format

The file format for training, testing, and validation data is the same as for SVM-Rank and LETOR datasets.

Each line in a training file represents one training example, and uses the following format:

<line> .=. <target> qid:<qid> <feature>:<value> <feature>:<value> ... <feature>:<value> # <info>
<target> .=. <positive integer>
<qid> .=. <positive integer>
<feature> .=. <positive integer>
<value> .=. <float>
<info> .=. <string>

where

  • <target>

    the relevance label. This is typically a value in the range [0, 1, 2, 3, 4] where 0 is not relevant, and 4 is perfect relevance, or in the range [0, 1] where 0 is not relevant and 1 is relevant.

  • <qid>

    An identifier for the query. A common approach is to assign a numeric identifier to each distinct query text, or group related query text under an identifier.

  • <feature>:<value>

    An identifier for a feature and its value. Features and their values are used to learn a ranking function.

    Important

    Features must be ordered by ascending feature identifier on each line.

  • <info>

    Comments for the example that are not used in learning, but help in identifying examples and aid in readability. Typically takes the form of <document id> <query text>.

Example

The following example has data for three different queries, where each example has two features.

4 qid:1 1:12.318474 2:10.573917 # 7555 rambo
3 qid:1 1:10.357876 2:11.95039  # 1370 rambo
3 qid:1 1:7.0105133 2:11.220095 # 1369 rambo
3 qid:1 1:0.0       2:11.220095 # 1368 rambo
0 qid:1 1:0.0       2:0.0       # 136278 rambo
0 qid:1 1:0.0       2:0.0       # 102947 rambo
0 qid:1 1:0.0       2:0.0       # 13969 rambo
0 qid:1 1:0.0       2:0.0       # 61645 rambo
0 qid:1 1:0.0       2:0.0       # 14423 rambo
0 qid:1 1:0.0       2:0.0       # 54156 rambo
4 qid:2 1:10.686391 2:8.814846  # 1366 rocky
3 qid:2 1:8.985554  2:9.984511  # 1246 rocky
3 qid:2 1:8.985554  2:8.067703  # 60375 rocky
3 qid:2 1:8.985554  2:5.66055   # 1371 rocky
3 qid:2 1:8.985554  2:7.300773  # 1375 rocky
3 qid:2 1:8.985554  2:8.814846  # 1374 rocky
0 qid:2 1:6.815921  2:0.0       # 110123 rocky
0 qid:2 1:6.081685  2:8.725065  # 17711 rocky
0 qid:2 1:6.081685  2:5.9764786 # 36685 rocky
4 qid:3 1:7.672084  2:12.72242  # 17711 bullwinkle
0 qid:3 1:0.0       2:0.0       # 1246 bullwinkle
0 qid:3 1:0.0       2:0.0       # 60375 bullwinkle
0 qid:3 1:0.0       2:0.0       # 1371 bullwinkle
0 qid:3 1:0.0       2:0.0       # 1375 bullwinkle
0 qid:3 1:0.0       2:0.0       # 1374 bullwinkle

The example includes additional whitespace to make it easier to read, but a single whitespace character between each piece of data on each line is sufficient.

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