Quick tips

• Check where the axis starts. Bars must start at zero; a cut axis turns small gaps into giant ones.
• Read the axis direction. If 0 sits at the top, a rising line means the opposite.
• Count the dates. Uneven intervals drawn at equal distances fake sudden jumps.
• Totals only go up. A cumulative chart can't show whether growth is slowing.
• Numbers beat pictures. When labels and bar heights disagree, trust the labels.