Lucene:首先不显示完全匹配

时间:2013-10-07 05:27:40

标签: java lucene rank scoring

我使用演示的IndexFiles和SearchFiles类来索引和搜索org.apache.lucene.demo数据包中的内容。

我的问题是当我使用包含多个单词的查询时,我没有得到具有完全匹配的结果。例如:

Enter query:
"natural language"
Searching for: "natural language"
298 total matching documents
1. download\researchers.uq.edu.au\fields-of-research\natural-language-processing
.txt
2. download\researchers.uq.edu.au\research-project\16267.txt
3. download\researchers.uq.edu.au\research-project\16279.txt
4. download\researchers.uq.edu.au\research-project\18361.txt
5. download\www.uq.edu.au\news\%3Farticle%3D2187.txt
6. download\researchers.uq.edu.au\researcher\2115.txt
7. download\ceit.uq.edu.au\content\2013-2014-summer-research-scholarship-project
s-dr-alan-cody%3Fpage%3D1.txt
8. download\ceit.uq.edu.au\content\2013-2014-summer-research-scholarship-project
s-dr-alan-cody%3Fpage%3D2.txt
9. download\ceit.uq.edu.au\content\2013-2014-summer-research-scholarship-project
s-dr-alan-cody.txt
10. download\www.ceit.uq.edu.au\content\2013-2014-summer-research-scholarship-pr
ojects-dr-alan-cody.txt
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与<:p>的结果不同

Enter query:
natural language
Searching for: natural language
54307 total matching documents
1. download\cyberschool.library.uq.edu.au\display_resource.phtml%3Frid%3D190.txt

2. download\cyberschool.library.uq.edu.au\display_resource.phtml%3Frid%3D576.txt

3. download\cyberschool.library.uq.edu.au\display_resource.phtml%3Frid%3D46.txt
4. download\espace.library.uq.edu.au\view\UQ%3A166163.txt
5. download\cyberschool.library.uq.edu.au\display_resource.phtml%3Frid%3D108.txt

6. download\cyberschool.library.uq.edu.au\display_resource.phtml%3Frid%3D70.txt
7. download\cyberschool.library.uq.edu.au\display_resource.phtml%3Frid%3D708.txt

8. download\researchers.uq.edu.au\fields-of-research\natural-language-processing
.txt
9. download\researchers.uq.edu.au\research-project\16267.txt
10. download\cyberschool.library.uq.edu.au\display_resource.phtml%3Frid%3D117.tx
t
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例如,第一个匹配的文档甚至不包含“language”关键字。

如果我在explain()课程中使用IndexSearcher方法,那么我将获得第一个结果:

1. download\cyberschool.library.uq.edu.au\display_resource.phtml%3Frid%3D190.txt
0.70643383 = (MATCH) sum of:
  0.5590494 = (MATCH) weight(contents:natural in 62541) [DefaultSimilarity], result of:
    0.5590494 = score(doc=62541,freq=4.0 = termFreq=4.0
), product of:
      0.8091749 = queryWeight, product of:
        4.4216847 = idf(docFreq=13111, maxDocs=401502)
        0.18300149 = queryNorm
      0.6908882 = fieldWeight in 62541, product of:
        2.0 = tf(freq=4.0), with freq of:
          4.0 = termFreq=4.0
        4.4216847 = idf(docFreq=13111, maxDocs=401502)
        0.078125 = fieldNorm(doc=62541)
  0.1473844 = (MATCH) weight(contents:language in 62541) [DefaultSimilarity], result of:
    0.1473844 = score(doc=62541,freq=1.0 = termFreq=1.0
), product of:
      0.5875679 = queryWeight, product of:
        3.2107275 = idf(docFreq=44012, maxDocs=401502)
        0.18300149 = queryNorm
      0.25083807 = fieldWeight in 62541, product of:
        1.0 = tf(freq=1.0), with freq of:
          1.0 = termFreq=1.0
        3.2107275 = idf(docFreq=44012, maxDocs=401502)
        0.078125 = fieldNorm(doc=62541)

如果我点击下一步并找到如下结果:

19. download\www.uq.edu.au\news\%3Farticle%3D2187.txt
0.47449595 = (MATCH) sum of:
  0.2795247 = (MATCH) weight(contents:natural in 35173) [DefaultSimilarity], result of:
    0.2795247 = score(doc=35173,freq=4.0 = termFreq=4.0
), product of:
      0.8091749 = queryWeight, product of:
        4.4216847 = idf(docFreq=13111, maxDocs=401502)
        0.18300149 = queryNorm
      0.3454441 = fieldWeight in 35173, product of:
        2.0 = tf(freq=4.0), with freq of:
          4.0 = termFreq=4.0
        4.4216847 = idf(docFreq=13111, maxDocs=401502)
        0.0390625 = fieldNorm(doc=35173)
  0.19497125 = (MATCH) weight(contents:language in 35173) [DefaultSimilarity], result of:
    0.19497125 = score(doc=35173,freq=7.0 = termFreq=7.0
), product of:
      0.5875679 = queryWeight, product of:
        3.2107275 = idf(docFreq=44012, maxDocs=401502)
        0.18300149 = queryNorm
      0.33182758 = fieldWeight in 35173, product of:
        2.6457512 = tf(freq=7.0), with freq of:
          7.0 = termFreq=7.0
        3.2107275 = idf(docFreq=44012, maxDocs=401502)
        0.0390625 = fieldNorm(doc=35173)

哪个页面本身包含完全关键字“自然语言”。所以我的问题是:

1)为什么Lucene不会先显示完全匹配?

2)为什么Lucene会显示甚至不包含关键字的结果?

3)我在哪里/如何改变它以便它首先显示完全匹配的那些然后更相关的那些?

1 个答案:

答案 0 :(得分:0)

1 - 无意。请参阅Lucene query syntax上的文档。查询natural language是由两个术语组成的查询。 Lucene本身并不偏好这些条款紧密相连。如果要查找完全匹配,则短语查询是正确的方法,例如"natural language"

2 - 包含解释的两个结果都包含两个术语的匹配项,请参阅:

0.2795247 = (MATCH) weight(contents:natural in 35173) [DefaultSimilarity], result of:
  0.2795247 = score(doc=35173,freq=4.0 = termFreq=4.0
...
0.19497125 = (MATCH) weight(contents:language in 35173) [DefaultSimilarity], result of:
  0.19497125 = score(doc=35173,freq=7.0 = termFreq=7.0

根据Lucene的说法,它在该文档中发现了4次“自然”一词,在内容字段中发现了7次“语言”(我假设它是您的默认字段)。

3 - 查看查询解析器语法,了解对您最有意义的内容。听起来你可能会发现Proximity Searches很有用。

如果您只想简单地获得其他人的短语匹配,您可以使用以下内容:

"natural language" natural language