README.md

Predict-next-order-of-users

My solution for the Instacart Market Basket Analysis competition hosted on Kaggle.

Task Description

This task is reformulated as a binary classification problem: given a user, a target product, and the user's purchase history, predict whether the target product will appear in the user's next order. The evaluation metric is the F1-score between the set of predicted products and the set of true products.

Data Description

The dataset is an open-source dataset provided by Instacart (source):

This anonymized dataset contains a sample of over 3 million grocery orders from more than 200,000 Instacart users. For each user, we provide between 4 and 100 of their orders, with the sequence of products purchased in each order. We also provide the week and hour of day the order was placed, and a relative measure of time between orders.

Below is the full data information (source):

orders (3.4m rows, 206k users):

• order_id: order identifier
• user_id: customer identifier
• eval_set: which evaluation set this order belongs in (see SET described below)
• order_number: the order sequence number for this user (1 = first, n = nth)
• order_dow: the day of the week the order was placed on
• order_hour_of_day: the hour of the day the order was placed on
• days_since_prior: days since the last order, capped at 30 (with NAs for order_number = 1)

products (50k rows):

• product_id: product identifier
• product_name: name of the product
• aisle_id: foreign key
• department_id: foreign key

aisles (134 rows):

• aisle_id: aisle identifier
• aisle: the name of the aisle

deptartments (21 rows):

• department_id: department identifier
• department: the name of the department

order_products__SET (30m+ rows):

• order_id: foreign key
• product_id: foreign key
• add_to_cart_order: order in which each product was added to cart
• reordered: 1 if this product has been ordered by this user in the past, 0 otherwise

where SET is one of the following evaluation sets (eval_set column in orders):

• "prior": orders prior to that users most recent order (~3.2m orders)
• "train": training data supplied to participants (~131k orders)
• "test": test data reserved for machine learning competitions (~75k orders)

Approach

Data Exploratory Analysis

• Try to figure out which features may have high impact on our prediction model.

Extract features (data_preprocessing.py)

Product features

• number of apearance in all the history orders
• total reorder number
• reorder ratio (product level)
• number of users who purchased this product
• average and standard deviation of add_to_cart_order
• average and standard deviation of purchase day_of_week (Monday, Tuesday, ...)
• average and standard deviation of purchase hour_of_day (8 am, 9am, ...)
• recency (captures if the product is generally brought more in users earlier orders or later orders)
• number of orders of user who bought this product
• number of users who purchased this product only once / more than once

User features

• number of Aisles/Departments a user purchased products from
• number of total history orders of a user
• reorder ratio (user level)
• average and standard deviation of days between history orders
• average and standard deviation of number of products purchased in the same order
• number of total / distinct products purchased
• average and standard deviation of add_to_cart_order (user level)
• average and standard deviation of interval between two orders which contained the same product

Apply cross-validation to choose hyperparameters for Gradient Boosting Descision Tree (lgb_userCV.py)

• I used lightGBM, which is a high performance gradient boosting framework developed by Microsoft.
• A 5-fold cross-validation on users was applied.

Analyze cross-validation results (loadCVResult.py)

• Analyzed saved cross-validation results and chose best 3 sets of parameters.

Train models with selected parameters (lgbPredict.py)

Optimize F1-score

• I followed the work of Dr. Nan in ICML 2012.