Automated Personalization uses a Random Forest algorithm to personalize

Random Forest is a leading machine-learning approach. In data-science terms, it is an ensemble classification or regression method that works by constructing many decision trees based on visitor and visit attributes. Within Target, Random Forest is used to determine which experience is expected to have the highest likelihood of conversion (or highest revenue per visit) for each specific visitor. For example, visitors who use Chrome, are gold loyalty members, and access your site on Tuesdays might be more likely to convert with Experience A. Visitors from New York might be more likely to convert with Experience B. For more information about Random Forest in Target, see Random Forest Algorithm.

The personalization model optimizes for each visit

  • The algorithm predicts a visitor’s likelihood of conversion (or estimated revenue from conversion) to serve the best experience.
  • A visitor is eligible for a new experience upon the end of an existing session, unless that visitor is in the control group. If the visitor is in the control group, the experience that the visitor sees on the first visit is the same experience seen in subsequent visits.
  • The experience presented does not change within a session to maintain visual consistency.

The personalization model adapts to changes in visitor behavior

  • The multi-arm bandit ensures that the model is always “spending” a small fraction of traffic to continue learning throughout the life of the activity and to prevent over-exploitation of previously learned trends.
  • The underlying models are rebuilt every 24 hours using the latest visitor behavior data to ensure that Target is always using changing visitor preferences.
  • If the algorithm can’t determine winning experiences for individual visitors, it automatically switches to showing the overall best-performing experience, while still continuing to look for personalized winners. The best-performing experience is found using Thompson Sampling.