A top_down, progressive deepening approach:
- First find high-level strong rules:
milk ® bread [20%, 60%].
- Then find their lower-level “weaker” rules:
2% milk ® wheat bread [6%, 50%].
A transaction item that supports x also supports all ancestors of x
Support will be weaker for lower levels, use different thresholds
Find the purchase patterns for fresh foods (SQL query)
related to category, content_spec, brand
from sales_transactions T, sales_item I
where T.bar_code = I.bar_code and I.category = ‘food’
and I.storage_period < 21