Java Reference

In-Depth Information

percentage
A value between 0 and 100 that represents a part of a

whole. For example, 75 percent indicates three quarters of a whole.

physical attribute
An object that corresponds to a field in a format-

ted file, or column in a database table.

physical dataset
Identifies data as a set of cases to be used as input

to data mining. Using tasks, physical attributes can be mapped to

logical attributes of a model's signature or logical data of a build

settings object. The data referenced by a
physical dataset
object can be

used in model building, scoring (apply), lift computation, statistical

analysis, etc.

physical data record
A collection of named attribute values used as

input and output for single or multi-record scoring.

predictor
A logical attribute used as input to a supervised model or

algorithm to build a model. Also referred to as an independent vari-

able.

predictive data mining
Data mining that results in a model by

performing inference on build data, and attempting to predict out-

comes for cases in apply datasets. See also
descriptive data mining
.

prior probabilities
The set of prior probabilities, or
priors
, specifies

the distribution of categories, or classes, in the original population.

Through skewed sampling, such as stratified sampling, prior proba-

bilities will differ from the distribution observed in the build dataset.

Priors allow the algorithm to adjust predictions to reflect original

population distributions.

probability
A value between zero and one (0 … 1) that indicates

the likelihood of an event. Zero indicates there is no chance of the

event occurring. One indicates it is probabilistically certain the event

will occur.

quality of fit
In clustering, a value between zero and one that is a

measure of how well a given case fits in the predicted cluster.

Values closer to zero indicate a poor fit; values closer to one indicate

a good fit.

receiver operating characteristics (ROC)
A measure of comparison

between individual models to determine thresholds that yield a high

proportion of positive hits. ROC curves aid users in adjusting the

cost matrix to minimizing error rates. ROC was originally used in

signal detection theory to gauge the true hit versus false alarm ratio

when sending signals over a noisy channel.

recode
A transformation that defines an explicit set of mappings,

where each mapping involves an original value and replacement (or

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