Definition
Probability model
A list of possible outcomes together with probabilities that describe their chances.
Continue from this idea into connected AXIO math.
Outcomes plus chances; all the chances add to 1.
Boundary: A short list of experimental results is data. It becomes evidence for a model only after probabilities are estimated or assigned and checked.
What it means
First say what can happen. Then give each outcome its share of the total chance. The shares may be equal or unequal, but together they must make one whole chance.
Remember it
Outcomes plus chances; all the chances add to 1.
Example
A spinner has four equal sections: two red, one blue, and one green. A color model is red 1/2, blue 1/4, green 1/4. The probabilities total 1.
Watch for
A short list of experimental results is data. It becomes evidence for a model only after probabilities are estimated or assigned and checked.
Common mix-up
A probability model does not require equal chances; a uniform model is the special case in which all outcomes are equally likely.
Exact meaning
A probability model specifies the possible outcomes of a chance process and assigns probabilities from 0 to 1 so the probabilities of all outcomes total 1.