Distribution Parameter Summary

The following table lists valid parameter values for each Crystal Ball distribution. Distributions are listed alphabetically by type (continuous or discrete). The Oracle Crystal Ball Statistical Guide lists defaults for each parameter value.

Table 10. Distributions and Their Parameters  

Distribution

 

Type

Parameter 1

Parameter 2

Parameter 3

Parameter 4

Beta

Beta Distribution Parameter

continuous

alpha (greater than 0.3, alpha + beta must be less than 1000)

beta (greater than 0.3, alpha + beta must be less than 1000)

maximum value

minimum value

BetaPERT

BetaPERT Distribution Parameter

continuous

minimum value

likeliest value

maximum value

N/A

Exponential

Exponential Distribution Parameter

continuous

rate (greater than 0)

N/A

N/A

N/A

Gamma

Gamma Distribution Parameter

continuous

location

scale (greater than 0)

shape (greater than 0.05 and less than 1000)

N/A

Logistic

Logistic Distribution Parameter

continuous

mean value

scale (greater than 0)

N/A

N/A

Lognormal

Lognormal Distribution Parameter

continuous

location

mean value

standard deviation value

N/A

Maximum extreme

Maximum Extreme Distribution Parameter

continuous

likeliest

scale (greater than 0)

N/A

N/A

Minimum extreme

Minimum Extreme Distribution Parameter

continuous

likeliest

scale (greater than 0)

N/A

N/A

Normal

Normal Distribution Parameter

continuous

mean value

standard deviation value

N/A

N/A

Pareto

Pareto Distribution Parameter

continuous

location (greater than 0)

shape (greater than 0.05)

N/A

N/A

Student’s t

Student's.t Distribution Parameter

continuous

midpoint

scale (greater than 0)

degrees of freedom (integer between 1 and 30, inclusive)

N/A

Triangular

Triangular Distribution Parameter

continuous

minimum value

likeliest value

maximum value

N/A

Uniform

Uniform Distribution Parameter

continuous

minimum value

maximum value

N/A

N/A

Weibull

Weibull Distribution Parameter

continuous

location

scale (greater than 0)

shape (greater than 0.05)

N/A

Binomial

Binomial Distribution Parameter

discrete

probability (between 0 and 1)

trials (a whole number greater than 0 and less than 1000)

N/A

N/A

Discrete Uniform

Discrete Uniform Distribution Parameter

discrete

minimum (integer)

maximum (integer)

N/A

N/A

Geometric

Geometric Distribution Parameter

discrete

probability (between 0 and 1)

N/A

N/A

N/A

Hyper- geometric

Hyper-geometric Distribution Parameter

discrete

success

trials (whole number less than population)

population (whole number greater than 0 and less than 1000)

N/A

Negative binomial

Negative Binomial Distribution Parameter

discrete

probability (between 0 and 1)

shape (whole number greater than 0 and less than 1000)

N/A

N/A

Poisson

Poisson Distribution Parameter

discrete

rate value (between 0 and 1000)

N/A

N/A

N/A

Yes-No

Yes-No Distribution Parameter

discrete

probability (between 0 and 1)

N/A

N/A

N/A

Custom

Custom Distribution Parameter

custom

See Appendix A of the current Oracle Crystal Ball User's Guide.

N/A

N/A

N/A