Data Visualisation: Telling compelling stories with data


Data Visualisation

 

Have you ever struggled to make sense of complex data? In today's data-driven world, you're not alone, which is why the ability to present information in a graphical and visual way has become increasingly important. Let's explore how data visualisation can help us understand and communicate statistics more effectively.

 

Why visualise data?

The human brain can process visual information 60,000 times faster than textual information! That's why a well-designed chart or graph can instantly convey data patterns and trends that might take paragraphs to explain. When C&SD presents social or economic indicators, carefully chosen visualisations help readers grasp key insights at a glance.

Population and average annual growth rate, 1961 – 2021

Taking the above table and chart as an example, compared with the table, the chart can better express the trend of population size and its growth rate.

 

How to choosing the right visual?

Different stories need different visuals, see the 2021 Population Census results as examples:

  • Line charts excel at showing trends over time, like Hong Kong's population growth rate.

    • Hong Kong's population growth rate

     

  • Bar charts compare categories effectively - perfect for displaying marital status across age groups.

    • marital status across age groups

     

  • Pie charts work well for showing proportions, such as the distribution of housing types.

    • distribution of housing types

     

    Keys to effective visualisation

    Like a good story, effective data visualisation needs three essential elements:

    1. Accuracy: Numbers must be presented truthfully!

      2. Population by age group, 2021

      Look at the above pie charts showing population by age group - the 2D version clearly shows the proportions, while the 3D effects distort the actual values. Using consistent scales and proper proportions ensures that your audience gets reliable insights. A small visual distortion could lead to big misunderstandings.

       

    2. Visual hierarchy: Important information should stand out!

      3. Population by sex and year

      The chart on the left uses distinct colours and clear alignment to help readers grasp the population statistics by year and by sex instantly, while the colourful chart on the right can be very confusing and divert readers away from the main point. Through clever use of size, colour, and spacing, we guide readers to key information.

       

    3. Simplicity: Less is more!

      4. Distribution of working population by occupation, 2021

      Compare the above occupation breakdowns - the left version uses clean bars with direct labels, making the data instantly clear. The right version splits the same information across a chart and a table, making it harder to read. Simple design choices can make complex data easy to understand.

     

    From Data to Discovery

    Numbers tell stories - but only when presented properly! Whether you're exploring market trends or revealing hidden patterns, effective visualisation turns data into "aha!" moments. Ready to make your data speak? Let's start the journey of data visualisation!

     

     

    NG Hoi-chun, Jason
    Statistician
    28 February 2025