Evaluating data mining

Complete the sections in order, beginning with retrieval and method selection before applying the ideas in integrated contexts. No new required knowledge is introduced.

Extended examination responses reward accurate knowledge, sustained scenario application and a reasoned judgement. This worksheet models that progression using a community transport service, not wording from a live paper.

By the end, you will be able to

• plan an extended evaluation rather than list advantages;
• develop benefits and limitations through mechanisms;
• apply each point to scenario evidence;
• reach a substantiated judgement.

Reactivate: data mining discovers useful information by interrogating large data sets.

Scenario: travel-card data

A regional transport partnership stores several years of anonymised tap-on times, route identifiers, delays, ticket types and interchange records. It proposes mining the data to redesign evening services. Some journeys are incomplete because passengers occasionally forget to tap out, and unusual disruption days are mixed with ordinary operation.

Build an analytical paragraph

Claim: Mining could reveal repeated route-and-time combinations associated with overcrowding.

Mechanism: comparing millions of journeys can expose a pattern that individual complaints may miss.

Application: planners could test an extra evening vehicle on the affected route.

Evaluation: incomplete tap-outs and disruption days may distort estimated demand, so findings should be cleaned, separated by conditions and checked against later observations.

Mini-judgement: the pattern is useful evidence for a trial, not automatic proof that a permanent timetable change will work.

This structure turns a generic benefit into applied reasoning.

Guided six-mark plan

Plan two chains before writing:

• benefit: large journey set → previously hidden demand pattern → targeted service trial → passenger/operational outcome;
• limitation: incomplete or unrepresentative records → distorted pattern → poor timetable decision → mitigation.

Use the scenario nouns in every chain. ‘Faster’ or ‘better decisions’ earns little unless you explain what becomes faster or better and why.

Independent twelve-mark evaluation

Consider discovery value, scale, timeliness, cost, expertise, data quality, privacy/fairness, false relationships, validation and the scope of the decision. Select the factors that matter most; do not force every prompt into the answer. Conclude by stating the conditions under which the method should be used.

Examiner-style self-review

Underline each use of scenario evidence. Box every mechanism word such as because, therefore or which means. Circle the judgement. If a paragraph contains only a definition or named advantage, add discovery → action → consequence. If it claims certainty, add a validation condition.

Closed-book checkpoint

Complete each sentence from memory. There is no answer bank and correctness is held for teacher review.

Review your understanding

Before submitting, check that you can explain the central distinction in your own words, expose the intermediate state that supports your answer and apply the method in an unfamiliar context.