Statistics
Probability
A numerical measure of the likelihood that a specific event or outcome will occur.
What is Probability?
Probability is quantified as a number between 0 and 1. In frequentist statistics, it represents the long-run relative frequency of an event. In Bayesian statistics, it represents a degree of belief or certainty about an event.
Why Probability Matters
Probability provides the mathematical foundation for statistical inference, allowing researchers to quantify uncertainty and assess how likely it is that their observed results occurred by random chance.
Example
If a researcher pulls a random card from a standard deck, the probability of drawing a heart is 0.25.
Common Mistakes
- Misinterpreting a p-value as the probability that the null hypothesis is true.
- Falling victim to the gambler's fallacy: assuming that independent past events affect the probability of future random events.