National Data Science Competition 2019 by Shopee

Collaborated with Zheng Xingjian

We have won the Merit award. Our score is placed 16th on the leaderboard.

Explanation of approach

The following is our baseline code, with three NLP models and a simple linear blending.

LSTM https://www.kaggle.com/huikang/baseline-lstm-pymag-3cheating-2100/

CNN https://www.kaggle.com/huikang/mastercopy-conv1d-hk/ (the rest of the model is the same)

GRU https://www.kaggle.com/huikang/mastercopy-gru-hk/ (the rest of the model is the same)

Ensemble with simple linear blending https://www.kaggle.com/huikang/ensemble/

For preprocessing, we used 7 embeddings and pymagnitude, a library that approximates word embeddings. https://github.com/tonghuikang/ndsc/blob/master/working/ndsc-dataset-tokeniser-presented.ipynb

The result of the tokenisation is available at https://www.kaggle.com/huikang/ndsc900

Unique features of our solution:

• We used embeddings of size 2100, concatenating 5 embeddings from the English language, and one embedding in Malay and Indonesian each.
• We also used pymagnitude to tokenise the embedding, which approximates the embeddings of the nearest tokens if a token is not found in the corpus.
• We used 5-fold cross-validation, and separate models for each of beauty-mobile-fashion to make our submission competitive. - Some manual fine-tuning is done to ensure that parameters are close to optimal.

Takeaways and additional comments

• The winning team had only four hours of sleep every day and sacrificed their school work, and the effort necessary to produce a top solution.
• We intended to share a baseline kernel and screw the meta. However, we found something that worked then one week before the end, and then we poured in much effort to get to a competitive ranking.
• The baseline kernel was adapted from a kernel in Quora Kaggle competition. There are over 300 forks to this kernel in the competition participated by 360 teams.
• Data science is a less cancerous way to start coding seriously, but a competent tech worker still needs holistic competency - i.e. frontend backend and the ability to learn quickly
• Kaggle kernels is a good enough to do most of the data science work - 9 commit GPUs, 7 interactive GPUs. 20GB public and 20GB private dataset. Some version control.
• Cross-validation (aka StratifiedKFold) works and is important. 10-fold cross validation is the standard for data of this amount.
• Do consider the possibility of not using certain information. Here, the images did not improve our final solution as well as many of the teams.
• I also get to gauge the strength and number of data science enthusiasts in Singapore. There are many other teams which spent a lot of purposeful effort in the competition.
• I appreciate the organisers' recognition of the efforts of the participants to share information.