Shape and rate parameters
Definition
The two parameters of the gamma distribution. The shape parameter controls how peaked or spread the distribution is; the rate parameter (sometimes expressed as its inverse, the scale) controls the units. Together they allow the gamma to fit a wide range of right-skewed data.
Related terms
- Likelihood ratio (LR)
- The ratio of two conditional probabilities: the probability of the observed evidence given the prosecution's hypothesis (same source), divided by the probability...
- Parameters
- The numerical constants that define the specific shape of a distribution within its family. The normal distribution has two parameters (mean and...
- Probability distribution
- A function that assigns probabilities to each possible value (or range of values) of a random variable. It fully characterises the uncertainty...
- Rate parameter (lambda)
- The single parameter of the Poisson distribution, equal to both the mean and the variance of the distribution. In forensic contexts lambda...
- Right skew
- A distribution is right-skewed when its tail extends further to the right than to the left. Many forensic measurement quantities (trace concentrations,...
Explained in
- Common Distributions in Forensic ScienceThe two parameters of the gamma distribution. The shape parameter controls how peaked or spread the distribution is; the rate parameter (sometimes expressed as...