Oliver is using a bar chart that has a vertical (y) axis that increases by a factor of 10 (1, 10, 100, 1000, 10000), which is misleading for visual comparisons. This type of scale disproportionately emphasizes small differences between values that are relatively close together while minimizing the differences between significantly larger values. In this case, since Oliver’s sales are close to 1000 while his peers’ sales are at or above 1000, the scale can make it seem like the gap isn't that significant when, in reality, it may be more substantial if the data were presented more clearly.
A more accurate representation of Oliver's performance would involve using a linear scale for the vertical y-axis, such as 0, 200, 400, 600, 800, 1000, etc. This would allow for a more straightforward visual comparison of sales numbers, clearly highlighting that Oliver's sales figures are lower than those of his peers. Additionally, ensuring all data points appear within a close range would make the differences easier to assess. Another option is to display the values directly on each bar to provide an immediate quantitative representation of the sales figures.