Data

📊 Statistical Cycle Overview (Grades 10–12)

1. Posing Questions

• Identify issues or problems in context that require data investigation

• Formulate clear, relevant, and answerable statistical questions

• Understand the purpose and target population of an investigation

2. Collecting Data

• Population and Samples

  • Define population and sample

  • Understand representativity and bias

  • Differentiate between random and non-random samples

• Data Types

  • Categorical (qualitative) vs. numerical (quantitative)

  • Discrete vs. continuous data

  • Primary vs. secondary data sources

• Data Collection Methods

  • Surveys, interviews, questionnaires

  • Observation and measurements

  • Designing appropriate and unbiased questions

3. Organising and Representing Data

• Tally Tables and Frequency Tables

  • Grouped and ungrouped data

  • Cumulative frequency tables

• Data Displays (Charts and Graphs)

  • Bar graphs and double bar graphs

  • Histograms (for grouped data)

  • Pie charts

  • Line graphs

  • Broken line graphs (time-series)

  • Scatter plots (Grade 12)

  • Box-and-whisker plots (Grade 12)

• Scale, Axis, and Labels

  • Appropriate use of intervals, titles, and units

4. Summarising Data (Measures of Central Tendency and Spread)

• Measures of Central Tendency

  • Mean, median, and mode (Grade 10–12)

  • Compare and interpret differences between them

• Measures of Spread

  • Range (Grade 10–12)

  • Interquartile range (IQR) and box plots (Grade 12)

  • Identification of outliers

• Interpretation

  • Commenting on distribution (e.g., skewness, consistency)

  • Suitability of measures in context

5. Interpreting, Analysing, and Reporting Data

• Reading and Interpreting Graphs and Tables

  • Identify trends and patterns

  • Make comparisons between groups

  • Read off values accurately

• Critically Evaluating Data

  • Assess validity, reliability, and bias in data and sources

  • Interpret misleading graphs or data representations

• Drawing Conclusions

  • Use data to support decisions or claims

  • Evaluate appropriateness of conclusions in context

• Reporting

  • Use clear, relevant statistical language

  • Summarise findings based on evidence

Progression Across Grades

• Grade 10: Introduction to the statistical cycle, basic representations, and calculations.

• Grade 11: Greater focus on grouped data, graphs, critical thinking, and data interpretation.

• Grade 12: Advanced summaries, box-and-whisker plots, scatter plots, correlation, and more critical evaluation of data and reports.