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Cross-validation is employed repeatedly in building decision trees. One form of cross-validation leaves out a single observation at a time; this is similar to the jackknife. Another, K-fold cross-validation, splits the data into K subsets; each is held out in turn as the validation set. This avoids "self-influence".
The studentized bootstrap, also called bootstrap-t, is computed analogously to the standard confidence interval, but replaces the quantiles from the normal or student approximation by the quantiles from the bootstrap distribution of the Student's t-test (see Davison and Hinkley 1997, equ. 5.7 p. 194 and Efron and Tibshirani 1993 equ 12.22, p. 160):
One set, the bootstrap sample, is the data chosen to be "in-the-bag" by sampling with replacement. The out-of-bag set is all data not chosen in the sampling process. When this process is repeated, such as when building a random forest, many bootstrap samples and OOB sets are created. The OOB sets can be aggregated into one dataset, but each ...
An illustration for the concept of bootstrap aggregating. Bagging leads to "improvements for unstable procedures", [2] which include, for example, artificial neural networks, classification and regression trees, and subset selection in linear regression. [3] Bagging was shown to improve preimage learning.
Illustration of k-fold cross-validation when n = 12 observations and k = 3. After data is shuffled, a total of 3 models will be trained and tested. In k-fold cross-validation, the original sample is randomly partitioned into k equal sized subsamples, often referred to as "folds".
In particular, three data sets are commonly used in different stages of the creation of the model: training, validation, and test sets. The model is initially fit on a training data set, [3] which is a set of examples used to fit the parameters (e.g. weights of connections between neurons in artificial neural networks) of the model. [4]
Otto announced Bootstrap 4 on October 29, 2014. [15] The first alpha version of Bootstrap 4 was released on August 19, 2015. [16] The first beta version was released on August 10, 2017. [17] Otto suspended work on Bootstrap 3 on September 6, 2016, to free up time to work on Bootstrap 4. Bootstrap 4 was finalized on January 18, 2018. [18]
To demonstrate specificity Inheritance Inheritance is a key feature in CSS; it relies on the ancestor-descendant relationship to operate. Inheritance is the mechanism by which properties are applied not only to a specified element but also to its descendants. Inheritance relies on the document tree, which is the hierarchy of XHTML elements in a page based on nesting. Descendant elements may ...