Data interpretation is highly relevant for engineers because it tests reading data, checking units, comparing ratios and verifying statements under time pressure.

Core Definitions

Data interpretation

Standard definition: Extracting meaning, comparison and conclusions from numerical tables, charts or graphs.

Exam meaning: Table/chart बाट सही information र conclusion निकाल्ने skill।

Verification

Standard definition: Checking whether a statement follows from given data.

Exam meaning: दिइएको data बाट statement सही/गलत/निश्चित छैन भनेर जाँच्ने काम।

How To Think

Do not calculate immediately. First read title, unit, scale, time period and categories. Many DI errors come from missing thousand/million units or comparing absolute values when percentage is required.

Chart Reading

Every chart has metadata.

  • Title tells subject.
  • Axis tells variable and unit.
  • Legend identifies categories.
  • Scale controls value reading.
  • Time period controls trend interpretation.
  • Footnotes may change meaning.

Comparison Types

Know what the question is really asking.

Question Word Operation Example
Difference Subtract A – B
Ratio Divide A/B
Percentage share Part/total x 100 Sector share
Growth Change/original x 100 Yearly increase
Average Total/count Mean value

Formulas and Rules

  • Growth % = (new – old) / old x 100.
  • Share % = part / total x 100.
  • Average = total / number of values.
  • Ratio A:B = A/B or simplified A:B.
  • Pie chart angle = value / total x 360 degrees.

Step-by-Step Method

  • Read title, unit and scale.
  • Mark required rows/columns only.
  • Estimate before exact calculation.
  • Use option elimination if values are far apart.
  • For verification, classify statement as true, false or cannot be determined.

Worked Examples

  • If revenue rises from 80 to 100, growth = 20/80 x 100 = 25%.
  • If total users are 500 and mobile users 200, share = 40%.
  • A statement about cause cannot be verified from a table that only shows numbers, unless cause is given.
DI Skill Engineering Habit Exam Benefit
Unit check Read metadata Avoid scale error
Approximation Estimate first Save time
Validation Check statement against data Avoid assumption
Trend reading Compare over time Find increase/decrease

Exam Point

  • Unit and scale are part of the question.
  • Percentage growth uses old value as base.
  • Pie chart questions often require share and angle.
  • Cannot be determined is valid when data is insufficient.

Visual Practice

  • Practice table-to-chart conversion.
  • Mark axis and units on sample charts.
  • Draw pie chart share table.
  • Create true/false/cannot-determine drills.

Common Mistakes

  • Ignoring units like lakh, million or percent.
  • Using new value as growth base.
  • Assuming causes from correlation.
  • Calculating all data instead of required cells.

MCQ Revision

  • Growth percent formula?
  • Pie angle formula?
  • What does chart legend show?
  • What is cannot be determined?
  • Why read units first?

Final Summary

  • DI is disciplined data reading.
  • Metadata prevents errors.
  • Know difference, ratio, share, growth and average.
  • Verification requires evidence from data only.