Diagrammatic formats - pie charts, bar charts, and line graphs

Covering Assessment Criterion 1.5 of 3CO02 Principles of Analytics, this video focuses on three diagrammatic formats used to present data findings: pie charts, bar charts, and line graphs. Rather than treating these as interchangeable options, the video addresses the distinct purpose each format serves and the conditions under which each communicates data most effectively to an audience. The discussion is grounded in people practice contexts, with examples drawn from areas such as exit interview analysis, training budget allocation, recruitment channel comparison, and employee satisfaction surveying.

The video examines the specific circumstances in which each format succeeds and where each falls short. For pie charts, this includes the relationship between the number of categories and visual clarity, as well as the requirement that data represents parts of a meaningful whole. For bar charts, the video covers vertical and horizontal orientations alongside two structural variations — grouped bar charts and stacked bar charts — and addresses how axis construction can affect how comparisons are read. Line graphs are examined in terms of their capacity to display trends across time periods, including the use of multiple data series to set organisational metrics such as voluntary turnover rates against external benchmarks.

Underpinning all three formats is a decision-making framework built around the question each chart type is best suited to answer: composition, comparison, or change over time. The video applies this directly to people practice scenarios including absence rate tracking across twelve months, training completion rates by department, engagement scores from successive annual surveys, and time-to-hire monitoring. Each format is considered not only as a visual tool but as a means of enabling audiences to draw accurate conclusions from HR data.