Northwind Electronics ENTERPRISE

#500

Recommendation Engine

"Customers who bought this also bought" and personal picks, with the reason for every pick.

Technique: Item-based collaborative filtering (cosine) + content similarity + popularity fallback

Read the code: src/main/java/com/study/advlab/recommend/RecommendationService.java

Hit rate @5 - hybrid engine

52.6%

hide each customer's last purchase: is it in our top 5?

Hit rate @5 - best sellers only

36.7%

the simple baseline to beat

Customers tested

196

"leave one out" offline evaluation

Personal picks for

Aisha Brown is in the segment Mobile first - the engine does NOT read the segment; it only learns from what people bought.

Bought before

Orbix Note 12 · Phones Sep 26
Zentek Wireless Mouse · Accessories Jun 26
Lumio One 5G · Phones Jun 26
Lumio Mini · Phones May 26
Lumio Watch Pro · Smartwatches May 26
Zentek 65W Charger · Accessories Mar 26

Recommended

1. Orbix Lite 15,190 THB

Customers who bought "Lumio One 5G" also bought this

score 0.48

collaborative 0.14 content 1.0 score = 0.75 × min(1, 2.2 × cf) + 0.25 × content

2. Kairo Fit 3 8,590 THB

Customers who bought "Lumio One 5G" also bought this

score 0.479

collaborative 0.205 content 0.56 score = 0.75 × min(1, 2.2 × cf) + 0.25 × content

3. Kairo Pro Max 11,690 THB

Customers who bought "Lumio One 5G" also bought this

score 0.439

collaborative 0.167 content 0.65 score = 0.75 × min(1, 2.2 × cf) + 0.25 × content

4. Sonara Run GPS 5,990 THB

Customers who bought "Lumio One 5G" also bought this

score 0.378

collaborative 0.131 content 0.65 score = 0.75 × min(1, 2.2 × cf) + 0.25 × content

5. Kairo Edge 39,190 THB

Customers who bought "Lumio Watch Pro" also bought this

score 0.361

collaborative 0.121 content 0.65 score = 0.75 × min(1, 2.2 × cf) + 0.25 × content

6. Zentek USB-C Dock 1,190 THB

Customers who bought "Lumio Watch Pro" also bought this

score 0.346

collaborative 0.081 content 0.85 score = 0.75 × min(1, 2.2 × cf) + 0.25 × content

7. Voltix USB-C Cable 3,990 THB

Customers who bought "Zentek 65W Charger" also bought this

score 0.324

collaborative 0.098 content 0.65 score = 0.75 × min(1, 2.2 × cf) + 0.25 × content

8. Voltix Power Bank 20000 3,290 THB

Customers who bought "Zentek 65W Charger" also bought this

score 0.319

collaborative 0.109 content 0.56 score = 0.75 × min(1, 2.2 × cf) + 0.25 × content

Customers who bought this also bought

Product	Bought together	Similarity
Zentek USB-C Dock Accessories	3×	0.231
Novabyte Curve 34 Monitors	5×	0.213
Voltix USB-C Cable Accessories	4×	0.211
Sonara Quiet 700 Headphones	3×	0.194
Pixelon Office 22 Monitors	3×	0.173
Zentek ProBook 16 Laptops	5×	0.167
Kairo Edge Phones	2×	0.167
Pixelon Vision 27 4K Monitors	4×	0.153

Cosine similarity

Each product is a list of the customers who bought it. Two products are similar when many of the same customers bought both:

sim(A, B) = buyers(A ∩ B) / √(buyers(A) × buyers(B))

40 buyers each, 10 in common → 10 / √(40 × 40) = 0.25.