Probability fixes the parameter and varies the data, resulting in a normalized distribution where the probabilities sum to 1. Likelihood fixes the data and varies the parameter, resulting in a non-normalized curve whose integral does not equal 1.
Conditions: Both views are based on the same conditional expression P(x∣θ).; Probability view: parameter is fixed, data varies.; Likelihood view: data is fixed, parameter varies.
Probability fixes the parameter and varies the data, resulting in a normalized distribution where the probabilities sum to 1. Likelihood fixes the data and varies the parameter, resulting in a non-normalized curve whose integral does not equal 1.
Conditions: Both views are based on the same conditional expression P(x∣θ).; Probability view: parameter is fixed, data varies.; Likelihood view: data is fixed, parameter varies.
The likelihood function is L(p)=(710)⋅p7⋅(1−p)3. It represents the probability of observing 7 heads and 3 tails as a function of the unknown parameter p, the probability of heads.
Conditions: The number of tosses n=10.; The observed number of heads k=7.; p is the probability of heads on a single toss.
The likelihood function is L(p)=(710)⋅p7⋅(1−p)3. It represents the probability of observing 7 heads and 3 tails as a function of the unknown parameter p, the probability of heads.
Conditions: The number of tosses n=10.; The observed number of heads k=7.; p is the probability of heads on a single toss.
The probability distribution sums to 1 because it accounts for all possible data outcomes under a fixed model, satisfying the axioms of probability. The likelihood curve does not integrate to 1 because it measures relative support for different parameter values given fixed data, and is not constrained to be a probability distribution over the parameter space.
Conditions: Probability view: parameter fixed, data varies over the entire sample space.; Likelihood view: data fixed, parameter varies over its domain.
The probability distribution sums to 1 because it accounts for all possible data outcomes under a fixed model, satisfying the axioms of probability. The likelihood curve does not integrate to 1 because it measures relative support for different parameter values given fixed data, and is not constrained to be a probability distribution over the parameter space.
Conditions: Probability view: parameter fixed, data varies over the entire sample space.; Likelihood view: data fixed, parameter varies over its domain.