For decades, “data science” meant traditional analytics — Excel, SQL, Tableau. It is fundamentally retrospective: it looks at the past to explain the present. If a retailer wants to segment customers, a human writes the rule: “spends over $500 → VIP.”
The comfort of certainty
- Deterministic and auditable: trace any wrong number back to a specific cell.
- No black box: safe, predictable — and for a long time, enough.
The critical limitation
- Inflexible: cannot handle ambiguity or unstructured data.
- Brittle: human rules don’t scale to millions of variables; one typo breaks the chain.
Case study — the supply chain crash. A logistics firm’s rule said “order winter inventory in September.” When an unseasonal October heatwave struck, the system kept ordering heavy coats — obedient to an outdated rule. The warehouse overflowed; the system wasn’t wrong, just deaf.





