Implementasi Contextual Multi-Armed Bandit dengan Algoritma LinUCB untuk Rekomendasi Template pada Sistem Kampanye WhatsApp Berbasis Web

Reigan Chenartha (Universitas Pembangunan Jaya, Banten)
Denny Ganjar Purnama (Universitas Pembangunan Jaya, Banten)

TIN: TERAPAN INFORMATIKA NUSANTARA
Vol 7 No 5 (2026): October 2026

Uniform WhatsApp campaign templates may overlook differences in timing and audience characteristics. This study develops an adaptive and auditable template recommendation module for a web-based campaign system. Design Science Research Methodology guides problem identification, objective definition, artifact development, demonstration, and evaluation. The disjoint Linear Upper Confidence Bound (LinUCB) algorithm treats Informative, Persuasive, and Urgency templates as three available actions. A 19-dimensional context vector encodes day, time bucket, audience, and a bias term. Template selection maximizes a linear reward estimate plus an exploration bonus, while the selected action is updated using delivered, read, and replied rewards weighted at 0.2, 0.3, and 0.5. Synthetic evaluation comprises 30 trials of 100 contexts each, with an exploration parameter of 0.3 and parent seed 1790543727863. LinUCB achieves a mean total reward of 39.520 with a standard deviation of 0.631, compared with 36.800 and 1.790 for the context-blind baseline. The mean improvement is 7.39%, with a mean regret of 2.769. The contribution is an integrated context–decision–feedback workflow with decision logging, operator control, and repeated evaluation isolated from operational data. These findings support artifact feasibility in the synthetic environment; improvements in real recipient responses require field validation.