Problem with right Classification

platanas20

Hello again,

I created a project which i use the operator "Process Documents From Files" and i added 2 classes(negative and positive).Each folder consists of 50 txt with comments.Also i use the operator"Read Document" which reads a negative comment.My final purpose is to classify this comment in the class of the negative comments.But the result isn't right and the negative comment seems to be positive.Plz take a look to the code and post any suggestion you may have!And something else..Is there any classifier which does this job better than Naive Bayes?

Thanks a lot!!

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<process version="5.1.008">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="5.1.008" expanded="true" name="Process">
    <parameter key="encoding" value="UTF-8"/>
    <process expanded="true" height="494" width="681">
      <operator activated="true" class="text:read_document" compatibility="5.1.002" expanded="true" height="60" name="Read Document" width="90" x="45" y="210">
        <parameter key="file" value="H:\Epifaneia Ergasias\RapidMiner\negative_comment.txt"/>
        <parameter key="encoding" value="UTF-8"/>
      </operator>
      <operator activated="true" class="text:process_documents" compatibility="5.1.002" expanded="true" height="94" name="Process Documents" width="90" x="179" y="300">
        <parameter key="parallelize_vector_creation" value="true"/>
        <process expanded="true" height="519" width="561">
          <operator activated="true" class="text:tokenize" compatibility="5.1.002" expanded="true" height="60" name="Tokenize (2)" width="90" x="45" y="30"/>
          <operator activated="true" class="text:filter_stopwords_dictionary" compatibility="5.1.002" expanded="true" height="60" name="Filter Stopwords (2)" width="90" x="246" y="30">
            <parameter key="file" value="H:\Epifaneia Ergasias\RapidMiner\STOPWORDS.txt"/>
            <parameter key="encoding" value="UTF-8"/>
          </operator>
          <operator activated="true" class="text:transform_cases" compatibility="5.1.002" expanded="true" height="60" name="Transform Cases" width="90" x="380" y="30"/>
          <connect from_port="document" to_op="Tokenize (2)" to_port="document"/>
          <connect from_op="Tokenize (2)" from_port="document" to_op="Filter Stopwords (2)" to_port="document"/>
          <connect from_op="Filter Stopwords (2)" from_port="document" to_op="Transform Cases" to_port="document"/>
          <connect from_op="Transform Cases" from_port="document" to_port="document 1"/>
          <portSpacing port="source_document" spacing="0"/>
          <portSpacing port="sink_document 1" spacing="0"/>
          <portSpacing port="sink_document 2" spacing="0"/>
        </process>
      </operator>
      <operator activated="true" class="text:process_document_from_file" compatibility="5.1.002" expanded="true" height="76" name="Process Documents from Files" width="90" x="112" y="75">
        <list key="text_directories">
          <parameter key="Positive" value="H:\Epifaneia Ergasias\RapidMiner\Positive"/>
          <parameter key="Negative" value="H:\Epifaneia Ergasias\RapidMiner\Negative"/>
        </list>
        <parameter key="encoding" value="UTF-8"/>
        <parameter key="parallelize_vector_creation" value="true"/>
        <process expanded="true">
          <operator activated="true" class="text:tokenize" compatibility="5.1.002" expanded="true" name="Tokenize"/>
          <operator activated="true" class="text:filter_stopwords_dictionary" compatibility="5.1.002" expanded="true" name="Filter Stopwords (Dictionary)">
            <parameter key="file" value="H:/Epifaneia Ergasias/RapidMiner/STOPWORDS.txt"/>
            <parameter key="encoding" value="UTF-8"/>
          </operator>
          <operator activated="true" class="text:transform_cases" compatibility="5.1.002" expanded="true" name="Transform Cases (2)"/>
          <connect from_port="document" to_op="Tokenize" to_port="document"/>
          <connect from_op="Tokenize" from_port="document" to_op="Filter Stopwords (Dictionary)" to_port="document"/>
          <connect from_op="Filter Stopwords (Dictionary)" from_port="document" to_op="Transform Cases (2)" to_port="document"/>
          <connect from_op="Transform Cases (2)" from_port="document" to_port="document 1"/>
          <portSpacing port="source_document" spacing="0"/>
          <portSpacing port="sink_document 1" spacing="0"/>
          <portSpacing port="sink_document 2" spacing="0"/>
        </process>
      </operator>
      <operator activated="true" class="x_validation" compatibility="5.1.008" expanded="true" height="112" name="Validation" width="90" x="313" y="120">
        <parameter key="parallelize_training" value="true"/>
        <parameter key="parallelize_testing" value="true"/>
        <process expanded="true" height="428" width="370">
          <operator activated="true" class="naive_bayes" compatibility="5.1.008" expanded="true" height="76" name="Naive Bayes" width="90" x="90" y="57"/>
          <connect from_port="training" to_op="Naive Bayes" to_port="training set"/>
          <connect from_op="Naive Bayes" from_port="model" to_port="model"/>
          <portSpacing port="source_training" spacing="0"/>
          <portSpacing port="sink_model" spacing="0"/>
          <portSpacing port="sink_through 1" spacing="0"/>
        </process>
        <process expanded="true" height="428" width="370">
          <operator activated="true" class="apply_model" compatibility="5.1.008" expanded="true" height="76" name="Apply Model (2)" width="90" x="45" y="30">
            <list key="application_parameters"/>
          </operator>
          <operator activated="true" class="performanceevaluator" compatibility="5.1.008" expanded="true" height="76" name="PerformanceEvaluator" width="90" x="212" y="30">
            <parameter key="accuracy" value="true"/>
            <list key="class_weights"/>
          </operator>
          <connect from_port="model" to_op="Apply Model (2)" to_port="model"/>
          <connect from_port="test set" to_op="Apply Model (2)" to_port="unlabelled data"/>
          <connect from_op="Apply Model (2)" from_port="labelled data" to_op="PerformanceEvaluator" to_port="labelled data"/>
          <connect from_op="PerformanceEvaluator" from_port="performance" to_port="averagable 1"/>
          <portSpacing port="source_model" spacing="0"/>
          <portSpacing port="source_test set" spacing="0"/>
          <portSpacing port="source_through 1" spacing="0"/>
          <portSpacing port="sink_averagable 1" spacing="0"/>
          <portSpacing port="sink_averagable 2" spacing="0"/>
        </process>
      </operator>
      <operator activated="true" class="apply_model" compatibility="5.1.008" expanded="true" height="76" name="Apply Model" width="90" x="514" y="300">
        <list key="application_parameters"/>
      </operator>
      <connect from_port="input 1" to_op="Process Documents from Files" to_port="word list"/>
      <connect from_op="Read Document" from_port="output" to_op="Process Documents" to_port="documents 1"/>
      <connect from_op="Process Documents" from_port="example set" to_op="Apply Model" to_port="unlabelled data"/>
      <connect from_op="Process Documents from Files" from_port="example set" to_op="Validation" to_port="training"/>
      <connect from_op="Validation" from_port="model" to_op="Apply Model" to_port="model"/>
      <connect from_op="Validation" from_port="averagable 1" to_port="result 1"/>
      <connect from_op="Apply Model" from_port="labelled data" to_port="result 2"/>
      <connect from_op="Apply Model" from_port="model" to_port="result 3"/>
      <portSpacing port="source_input 1" spacing="0"/>
      <portSpacing port="source_input 2" spacing="0"/>
      <portSpacing port="sink_result 1" spacing="0"/>
      <portSpacing port="sink_result 2" spacing="0"/>
      <portSpacing port="sink_result 3" spacing="0"/>
      <portSpacing port="sink_result 4" spacing="0"/>
    </process>
  </operator>
</process>

colo

Hi platanas,

did you already try a SVM classifier? As far as I know, they are not bad when classifying documents. But I'm not really familiar with classification tasks, I am recently working in the information extraction sector.

RapidMiner makes it pretty easy to test another method, so perhaps just give it a try?

Regards
Matthias