Slides -- A Smarter Chatbot

A Smarter Chatbot

San Diego Python Monthly Meetup by Hobson Lane Oct 24, 2019

Props to Parul Pandey

Human Initiative

Bot Initiative

Language Models

  • Bag of Words
  • TFIDF
  • Word2Vec
  • Universal Sentence Encoder

Bag of Words Vectors (TF)

Term frequency (count):

bow_vectors = [
    {'hello': 1, 'world': 1, '!': 1}
    {'goodbye': 1 'cruel': 2, 'world': 1, '.': 3}
    ]

TFIDF (TF / DF)

bow_vectors = [
    {'hello': 1, 'world': 1, '!': 1}
    {'goodbye': 1 'cruel': 2, 'world': 1, '.': 3}
    ]

Parul’s QA Bot

flag=True
print("ROBO: My name is Robo. I will answer your queries about Chatbots. If you want to exit, type Bye!")
while(flag==True):
    user_response = input()
...
    else:
        flag=False
        print("ROBO: Bye! take care..")

WordVec

Single layer neural net (equivalent to PCA):

  • predict next word
  • predict previous word
  • predict word 2 positions ago
  • …

WordVec Example

nlp = spacy.load('')
doc1 = nlp("Hello world!")
df = pd.DataFrame([term.vector for term in doc],
                  index=[term.text for term in doc])
            0     1    ...       298   299
Hello  2.52e-01  0.10  ... -5.19e-01  0.34
world -6.68e-03  0.22  ...  1.41e-03  0.10
!     -2.66e-01  0.34  ... -6.29e-02  0.16

DocVec Example

doc1 = nlp("Hello world!")
pd.DataFrame(df.sum(), columns=['doc1']).T
       0     1    ...   298  299
doc1 -0.02  0.66  ... -0.58  0.6

DocVec Example

doc2 = nlp('Goodbye cruel cruel world ...')
pd.DataFrame(df2.sum(), columns=['doc2']).T
      0     1    ...   298   299
doc2 -1.4  0.48  ... -0.52 -0.94

SpaCy Rocks!

docvec2 = nlp('Goodbye cruel cruel world ...').vector
pd.DataFrame(docvec2, columns=['doc2']).T
       0    1    ...  298   299
doc2 -0.28  0.1  ... -0.1 -0.19

Universal Sentence Encoder (USE)

Deep LSTM recurrent neural networks trained to:

  • Answer questions
  • Summarize sentences
  • Guess missing words

Next steps

  • Remember state
  • Smarter conversation manager
  • “Game play” with goal states (user satisfaction)

Dialog Tree

Props to Alfred Francis

Written on October 24, 2019