---
title: "Descriptive vs predictive data mining"
subject: "Data Mining"
chapter: 1
key: "semester_7/data_mining:dm-descriptive-predictive"
source: https://www.bctengineer.com/q/semester_7/data_mining/dm-descriptive-predictive
site: BCT Engineering
---

# Descriptive vs predictive data mining

Data Mining · Chapter 1: Introduction

- Asked in: year not given
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/data_mining/dm-descriptive-predictive
- Whole chapter: https://www.bctengineer.com/md/semester_7/data_mining/chapter-1

## Question

What is Data Mining? Differentiate between descriptive and predictive Data Mining.

## Short answer

Data mining discovers interesting, previously unknown patterns from large data sets. Descriptive mining describes existing data using clustering, association and summaries, mostly unsupervised. Predictive mining builds models from training data to predict unknown values using classification, regression and forecasting, mostly supervised. The goal of descriptive is what happened; predictive is what will happen.

## Answer

**Data mining** is the process of discovering interesting, previously unknown and useful patterns from large data sets, using techniques of statistics, machine learning and databases.

| Point | Descriptive data mining | Predictive data mining |
|---|---|---|
| Goal | Describe the general properties of existing data | Predict unknown or future values |
| Question | "What happened? What patterns exist?" | "What will happen?" |
| Approach | Presents the data as groups, rules and summaries | Builds a model from training data and applies it to new data |
| Learning | Mostly unsupervised | Mostly supervised |
| Techniques | Clustering, association rules, summarisation, sequence discovery | Classification, regression, time-series forecasting |
| Output | Clusters, rules, characteristics | Class label or numeric value |
| Example | Group customers by buying behaviour; find that bread and butter are bought together | Predict whether a loan applicant will default; forecast next month's sales |

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What is the goal of descriptive data mining?
   A. Predict future values
   B. Describe general properties and patterns of existing data
   C. Delete old data
   D. Build a model from labelled training data only
   Answer: B. Descriptive mining summarises existing patterns. (Key point: Descriptive goal)

2. Which technique is predictive?
   A. Clustering
   B. Association rules
   C. Classification and regression
   D. Summarisation
   Answer: C. Classification, regression and forecasting predict unknown values. (Key point: Predictive techniques)

3. Which learning type goes with each approach?
   A. Descriptive: mostly unsupervised; predictive: mostly supervised
   B. Descriptive: supervised; predictive: unsupervised
   C. Both unsupervised
   D. Both supervised
   Answer: A. Descriptive uses mostly unsupervised methods; predictive builds models from training data. (Key point: Learning type)

## Related in Data Mining

- [Data mining vs DW and applications](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adm-vs-dw-applications) — Data Mining, chapter 1
- [Data mining vs query tools](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adm-vs-query-tools) — Data Mining, chapter 1
- [Data mining and its applications](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adm-banking-biomedical) — Data Mining, chapter 1
- [CRM; security and privacy of data mining](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Acrm-security-privacy) — Data Mining, chapter 7
- [Where data mining is applicable](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adm-areas-applicable) — Data Mining, chapter 1
- [Architecture of data mining system](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adm-system-architecture) — Data Mining, chapter 1

## Related in other subjects

- [Data warehouse and data mining](https://www.bctengineer.com/question.md?key=semester_8%2Finformation_system%3Adata-warehouse-data-mining) — Information System, chapter 4, asked 2×
- [Short note: data mining and warehousing](https://www.bctengineer.com/question.md?key=semester_8%2Finformation_system%3Adata-mining-and-warehousing-note) — Information System, chapter 4
- [Data mining and business knowledge](https://www.bctengineer.com/question.md?key=semester_8%2Finformation_system%3Adata-mining-business-knowledge) — Information System, chapter 4
- [Text mining vs web usage mining](https://www.bctengineer.com/question.md?key=semester_8%2Finformation_system%3Atext-mining-vs-web-usage-mining) — Information System, chapter 7