1.3.6Unit 1: Lifestyle, Transport, Genes and Health
Perception of Risk vs Actual Risk — IAL Edexcel Linear Revision Notes & Topical Questions
5 min read 4 parts Lesson 24 of 29 Unit quiz
Curriculum Equation Key قوانين الرقم الهيدروجيني والاتزان الأيوني - pH & Acid-Base Equilibrium FormulasFast Exam Solution
pH = -log[H⁺] | pOH = -log[OH⁻] | pH + pOH = 14 | [H⁺][OH⁻] = 10⁻¹⁴
Word Equation & Conditions: الرقم الهيدروجيني = -لوغاريتم تركيز أيون الهيدروجين | pH + pOH = 14
Location & Specifications: الاتزان الأيوني، كيمياء 3 ثانوي، التحصيلي، و AP Chemistry.
Section 1 of 4Perceived and Actual Risk
Risk
- Risk Risk is the probability that a harmful event will happen, often given as a proportion or as a number in a given population.
Actual risk
- Actual risk This is the real probability worked out from reliable data collected from many people over time.
Perceived risk
- Perceived risk This is a person’s own judgement of how likely the event is, which is influenced by feelings and experience.
Gap
- Gap The two can differ widely, so people may worry about small risks but ignore much larger ones.
Section 2 of 4Why Perception Differs
Why Perception Differs
Overestimating
- Overestimating Dramatic media coverage, an unfamiliar hazard, severe consequences or personal experience can all make a risk seem larger than it is.
Underestimating
- Underestimating Familiar activities, benefits that are enjoyed and harm that is delayed make people discount risks such as smoking.
Control
- Control People feel safer when they are in control, for example driving, compared with being a passenger.
Understanding
- Understanding Poor understanding of statistics and chance leads to errors in judging risk.
Section 3 of 4Using Numbers Sensibly
1
Absolute risk expresses the chance of an event, such as 2 cases in 1000 people, giving a clear idea of how likely it is.
2
Relative risk compares the chance in two groups and can sound alarming even when the absolute risk is tiny.
3
For example, a rise from 2 to 4 cases per 1000 doubles the risk, a 100% increase, but the absolute risk increases by only 0.2 percentage points.
4
Good decisions require both figures, together with an understanding of the benefits and costs of the activity.
5
Public health messages should therefore give clear, balanced figures to help people make informed choices.
Section 4 of 4Exam Checklist & Tips
1.3.6 – Key Points for the Exam
- Risk The probability that a harmful event will occur.
- Perceived risk An individual’s opinion of how likely harm is.
- Absolute risk The actual chance of an event happening in a group.
- Relative risk A comparison of risk between two groups.
Common Mistakes
- Assuming that perceived risk equals actual risk.
- Describing a doubling of a very small risk as a large risk, ignoring the absolute figure.
- Saying that everyone underestimates risk; people also overestimate some risks.
- Using only anecdotes, instead of data from large studies, to judge risk.
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