1. Smart recommendation engine
of things to do in destination
Natural Language Processing and
Machine Learning
How to automatically categorize tours
and activities ?
July 2nd 2018

2. Introduction
MyLittleAdventure
@mylitadventure
Johnny RAHAJARISON
@brainstorm_me
johnny.rahajarison@mylittleadventure.com
2

3. Agenda
Introduction to machine learning
Why Natural Language Processing is so hard?
How do we process text?
Let’s try it out
Go further
3

4. What’s Machine Learning ?
Software that do something without being
explicitly programmed to, just by learning
through examples
Same software can be used for various tasks
It learns from experiences with respect to some task and
performance, and improves through experience
4

5. Unsupervised algorithms
Unsupervised algorithms
ClusteringAnomaly detection
5

6. Supervised algorithms
Supervised algorithms
ClassificationRegression
6

7. You said text, right?
7

8. Obviously, you said text
Not numbers
ContextPolysemy
Synonyms
Enantiosemy
Neologisms
Sarcasm
Names
Rare words
Common sense
Dialects
Non formal / abbrev.
8

9. Ambiguity?
9
I saw a man on a hill with a telescope.

10. Ambiguity?
10
I saw a man on a hill with a telescope.

11. Text should be prepared
11

12. Let’s clean our text first
['one', 'morn', 'when', 'gregor', 'samsa', 'woke', 'from', 'troubl', 'dream', 'he', 'found',
'himself', 'transform', 'in', 'hi', 'bed', 'into', 'a', 'horribl', 'vermin', 'He', 'lay', 'on',
'hi', 'armour-lik', 'back', 'and', 'if', 'he', 'lift', 'hi', 'head', 'a', 'littl', 'he', 'could',
'see', 'hi', 'brown', 'belli', 'slightli', 'dome', 'and', 'divid', 'by', 'arch', 'into', 'stiff',
'section', 'the', 'bed', 'wa', 'hardli', 'abl', 'to', 'cover', 'it', 'and', 'seem', 'readi', 'to',
'slide', 'off', 'ani', 'moment', 'hi', 'mani', 'leg', 'piti', 'thin', 'compar', 'with', 'the',
'size', 'of', 'the', 'rest', 'of', 'him', 'wave', 'about', 'helplessli', 'as', 'he', 'look',
'what', "'s", 'happen', ‘to']
✓ Tokenize sentences
✓ Tokenize words
✓ Transliterate
✓ Normalize
✓ Filter out
(punctuation, special characters, stop words)
✓ Use a stemmer and / or a lemmatizer
("be" = am, are, is; “vari" = variation, vary, varies, variables)
12

13. A bag of words
“John","likes","to","watch","movies","Mary","likes","movies","too"
{"John":1,"likes":2,"to":1,"watch":1,"movies":2,"Mary":1,"too":1}
{131:1, 132:2, 133:1, 134:1, 135:2, 136:1, 137:1}
[1, 2, 1, 1, 2, 1, 1]
Each unique word in our dictionary will correspond to a feature
13

14. Count of documents
TF-IDF
TF (Term Frequencies)
Occurrences of a term
IDF (Inverse Document Frequency)
log( )Count of documents where terms appear
Total words in each document
14

15. Another way: use words embeddings
Words embeddings captures relative meaning
Use vectors to get comprehensive geometry of words
15

16. Paris - France + China = Beijing
Another way: use words embeddings
16

17. Example of “movies" vector
movies -0.34582 0.057328 0.1328 0.22376 0.10161 0.52948 -0.30199 0.45676 -0.37643 -0.51857 0.67325 -0.012444 -0.099021 0.43823
-0.28905 -1.0183 -0.0062387 -0.32893 0.55547 0.44181 0.31524 0.29909 0.51605 0.32109 0.021471 0.67909 0.037333 -0.42321
0.56517 0.47979 -0.63307 0.1126 0.0050579 -0.18879 -0.87478 -0.29481 -0.70824 -0.072256 0.1614 0.34523 0.61872 -0.036932
-0.43343 0.29604 0.18671 -0.33384 0.50628 -0.013876 0.46303 0.19298 0.16783 -0.55786 -0.16947 -0.27382 0.31027 0.10974 0.12819
0.23538 0.038003 -0.077524 -0.23291 0.044094 0.36325 0.20611 0.55571 -0.022715 -0.04996 0.32312 0.44176 0.25272 0.15159
0.22682 -0.10425 0.73375 0.66572 -0.55885 0.082242 -0.13387 0.31042 -0.38443 -0.38631 -0.7518 0.6706 -0.17495 0.056298 0.82038
0.41573 -0.12316 0.28437 -0.19324 -0.13485 0.28862 -0.37817 0.37268 0.01515 0.39123 0.059544 -0.074006 -0.17152 -1.1523
0.26541 0.082314 0.17914 -0.089861 -0.20884 0.29248 -0.60263 -0.0024285 0.24521 -0.5427 -0.074404 0.14034 0.0085891 -0.37351
0.23573 0.1493 -0.14038 0.11725 -0.51013 -0.64531 0.1329 0.075911 -0.10827 0.22077 -0.086253 0.4096 0.052314 0.40964 -0.030506
0.30572 -0.40694 -0.11773 0.21586 0.14448 0.23419 -0.23401 0.06811 0.29447 -0.4086 0.88777 -0.19477 -0.18847 0.10324 -0.24593
-0.10173 -0.43226 -0.091173 -0.092602 -0.23385 -0.16498 0.22057 0.11014 -0.25018 -0.43089 0.19759 0.11762 -0.045432 0.13331
0.032684 -0.21702 0.35082 -0.40466 -0.02425 -0.22637 0.0094442 0.72848 0.10286 0.27199 -0.40396 0.22366 -0.039481 -0.17164
-1.7307 0.3706 -0.13711 0.2295 -0.34432 -0.024381 -0.093941 -0.29861 -0.33164 -0.12931 -0.11218 0.047052 0.40442 0.0043382
0.22364 -0.31537 0.1987 -0.46108 -0.35126 -0.14584 0.17765 0.10869 -0.14434 -0.6152 -0.5874 0.014977 -0.1691 -0.46926 1.3959
-0.15449 -0.24167 -0.002575 0.4758 -0.044786 -0.21345 0.22983 -0.34356 -0.43402 -0.45719 -0.29775 -0.053295 0.50132 -0.24066
0.45762 0.095118 0.21008 0.71912 0.028577 -0.64176 0.1314 0.21556 -0.12536 -0.3298 -0.07123 0.35428 -0.3787 0.12348 -0.060439
0.19217 -0.29951 -0.73189 -0.33589 0.449 0.22654 1.0404 0.019947 -0.74711 0.071042 0.067809 0.36341 -0.32579 -0.11085 -0.24507
-0.13518 -0.44326 0.022784 -0.57252 0.33756 -0.23411 -0.062955 -0.35353 1.0497 -0.14938 -0.57772 0.27652 -0.28787 -0.0040621
0.25113 0.40818 -0.13227 0.016032 -0.55465 0.0021098 -0.27755 0.16082 -0.055202 0.21104 0.58412 0.42842 -0.047253 0.10542
0.027478 0.30911 0.31792 -1.8564 0.014412 -0.29748 -0.70103 -0.068219 -0.53071 -0.10661 0.028596 0.081479 0.34323 -0.047833
0.023129 0.028697 0.33859 -0.20706 -0.0025571 -0.18267 -0.26946 -1.1064 -0.31228 -0.13101 0.1161 -0.068647 -0.09988
Another way: use words embeddings
17

18. [[], 2*[], [], [], 2 *[-0.34582, 0.057328, … 0.22376, 0.10161], [], []]
{"John":1,"likes":2,"to":1,"watch":1,"movies":2,"Mary":1,"too":1}
{131:1, 132:2, 133:1, 134:1, 135:2, 136:1, 137:1}
[1, 2, 1, 1, 2, 1, 1]
Another way: use words embeddings
Embeddings vector for “movies"
18

19. Let’s predict
19

20. Recipe
Prepare
Training / Test
data
Files, database,
cache, data flow
Selection of model,
and (hyper) parameters
Train algorithm
Use or store your
trained estimator
Make
predictions
Measure accuracy
precision
Measure
20

21. Collect our training & test dataset
Food Label Vectorized
Eiffel Tower with Dinner
[ 0., 0., 0., 0., 0.5, 0.5, 0., 0., 0., 0., 0., 0., 0., 0., 0.,
0., 0., 0., 0., 0.5, 0., 0.5],
Skip the line Eiffel Tower
[ 0., 0., 0., 0., 0., 0.3967171 , 0., 0., 0., 0.47792296, 0., 0.,
0., 0., 0., 0.47792296, 0.47792296, 0., 0., 0.3967171 , 0., 0.],
Louvre Museum fast track
[ 0., 0., 0., 0., 0., 0., 0.5, 0., 0., 0., 0.5, 0.5, 0., 0., 0.,
0., 0., 0., 0., 0., 0.5, 0.],
Gourmet tour of Paris
[ 0., 0., 0., 0., 0., 0., 0., 0.58910044, 0., 0., 0., 0.,
0.41798437, 0.48900396, 0., 0., 0., 0., 0.48900396, 0., 0., 0.],
Segway tour of city’s highlights
[ 0., 0., 0.48838773, 0., 0., 0., 0., 0., 0.48838773, 0., 0., 0.,
0.3465257 , 0., 0.48838773, 0., 0., 0., 0.40540376, 0., 0., 0.],
Dinner cruise with Champagne
[ 0., 0.54408243, 0., 0.54408243, 0.45163515, 0., 0., 0., 0., 0.,
0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.45163515],
Aquarium of Paris ticket
[ 0.55967542, 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,
0.39710644, 0.46457866, 0., 0., 0., 0.55967542, 0., 0., 0., 0.]
… …
21

22. Choose a classifier algorithm
22

23. A few recommendations
Naive Bayes / Logistic Regression
Decision Trees
Random Forest
Gradient Boosting
SVM
Neural Networks
23

24. Let’s measure
Food Label Prediction
Eiffel Tower with Dinner 0.83
Gourmet tour of Paris 0.96
Dinner cruise with Champagne 1.0
Segway tour of city’s highlights 0.03
Orsay dedicated entrance 0.02
3 course meal in Eiffel Tower 0.97
Cooking class in Paris 0.89
Moulin Rouge Paris dinner show 0.91
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Training set
Real datas

25. 25

26. Go further
26

27. There is way more
Cross validation dataset
N-Grams
Wrong user content
Misspellings & typos
Hard to get training data
Harder languages or transliterations issues
Memory / computing limitations
Online learning & Stacking
27

28. Some resources
https://www.slideshare.net/mylittleadventure/introduction-machine-learning-by-mylittleadventure
http://scikit-learn.org/stable/tutorial/text_analytics/working_with_text_data.html
https://bit.ly/2uL954v
NLTK
Book
Stanford’s GloVe
DatasetCourse
Andrew Ng (coursera)
Platform
28
Libraries

29. Thank you
July 2nd 2018
Questions ?
@mylitadventure
@brainstorm_me
johnny.rahajarison@mylittleadventure.com