Definitions for "Jackknifing"
A statistical method of numerical resampling based on deleting a portion of the original observations in subsequent samples.
A technique for estimating the confidence in an internal branch of a tree by resampling the original data set without replacement, so that no datum is used more than once. With DNA sequences a certain percentage of the positions are sampled and a new tree is reconstructed. The jackknife value for the branch is the percentage of such resamplings (typically 500 to 1000) that recover the branch. Compare Bootstrapping, in which resampled data may be used more than once.
a numerical resampling technique. It eliminates one observation from the original data set at the time, and thus the number of new data sets is equal to the number of observations in the original data set. This techniques allows for calculating variance within data set. See --bootstrapping.
Keywords:  trailer, icy, skids, tractor, push
The trailer over-turns the tractor, pushing the tractor drive wheels sideways, forcing the combination into a V-shaped attitude, resulting in a complete loss of control with no possibility of recovery.()
Jackknifing means the accidental folding of an articulated vehicle (i.e. one towing a trailer) such that it resembles the acute angle of a folding pocket knife. If a vehicle towing a trailer skids, the trailer can push it from behind until it spins round and faces backwards. This may be caused by equipment failure, improper braking, or adverse road conditions such as an icy road surface.