Social Media Mining: An Introduction

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CUUS2079-05 CUUS2079-Zafarani 978 1 107 01885 3 January 13, 2014 19:23


136 Data Mining Essentials

Data


  1. Describe methods that can be used to deal with missing data.

  2. Given a continuous attribute, how can we convert it to a discrete
    attribute? How can we convert discrete attributes to continuous ones?

  3. If you had the chance of choosing either instance selection or feature
    selection, which one would you choose? Please justify.

  4. Given two text documents that are vectorized, how can we measure
    document similarity?

  5. In the example provided for TF-IDF (Example 5.1), the word “orange”
    received zero score. Is this desirable? What does a high TF-IDF value
    show?


Supervised Learning


  1. Provide a pseudocode for decision tree induction.

  2. How many decision trees containingnattributes and a binary class can
    be generated?

  3. What does zero entropy mean?

  4. What is the time complexity for learning a naive Bayes classifer?
    What is the time complexity for classifying using the naive Bayes
    classifier?
    Linear separability: Two sets of two-dimensional instances are
    linearly separable if they can be completely separated using one
    line. In n-dimensional space, two set of instances are linearly
    separable if one can separate them by a hyper-plane. A classical
    example of nonlinearity is the XOR function. In this function, the
    two instance sets are the black-and-white instances (see Figure 5.9),
    which cannot be separated using a single line. This is an example
    of a nonlinear binary function. Can a naive Bayes classifier learn
    nonlinear binary functions? Provide details.
    What about linear separability andK-NN? AreK-NNs capable of
    solving such problems?


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Figure 5.9. Nonlinearity of XOR Function.
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