Charts, Tables, and Data Visualization
Domain focus: whether the chart answers the question the slide asks, and whether the data is honest and legible.
Choose by question type
Line for trend over time; column or bar for comparison across categories; bar rather than column when labels are long; pie only for parts of a whole with five or fewer slices; scatter for correlation; waterfall for cumulative change. Sort categories by value unless the categories have a natural order. Use one accent colour for the point you are making and grey for context.
Chart mechanics
Switch Row/Column fixes the common problem of series and categories reversed. Edit Data opens the embedded workbook; charts keep their data inside the deck, so a chart is not automatically linked to an external file. Direct data labels usually beat a legend plus gridlines. Never truncate a value axis to exaggerate differences, never use 3-D charts, and avoid dual axes unless units are truly different.
Tables
Tables are for exact lookup, not persuasion; keep them to roughly five rows and five columns, band rows for tracking, right-align numbers, and set a header row. Merged cells destroy screen-reader navigation - use them sparingly or not at all.
Worked example
Twelve monthly revenue figures for six regions. For the trend, plot one line for total revenue rather than 72 columns. For the regional comparison, use a horizontal bar chart sorted descending, because region names are long and ranking is the question. Reasoning: the original 72-column chart forced the audience to compare lengths across a crowded axis instead of reading a trend.
Traps that cost marks
Pie charts with nine slices; a y-axis starting at 80; unlabelled units; pasted chart images that cannot be edited; default legends and gridlines left in; tables reproduced as screenshots.