Subject Matter

• Arrows are often used to depict air pressure in illustrations and models.
• Force and pressure are two related, yet distinct concepts. People tend to confuse the two. Models that use arrows can fuel this confusion.
• We can choose to use other models and/or to be aware of how models with arrows can reinforce confusion between force and pressure.

Causality

• If a passive causal agent is perceived as "active," it is more likely to be recognized.
• Being unaware of non-obvious or passive causes limits the scope of variables one considers when generating explanations for given events.