Six Sigma Statistical Terms
NULL HYPOTHESIS
An assertion to be proven by statistical analysis where two or more data sets are stated to be from the same population.
ONE-SIDED ALTERNATIVE
The value of a parameter which has an upper bound or a lower bound, but not both.
ORDINAL
Ordered categories (ranking) with no information about distance between each category, i.e., rank ordering of several measurements of an output parameter.
ORDINATE
The vertical axis of a graph.
OUT OF CONTROL
Condition which applies to statistical process control chart where plot points fall outside of the control limits or fail an established run or trend criteria, all of which indicate that an assignable cause is present in the process.
PARAMETER
A constant defining a particular property of the density function of a variable.
PARETO DIAGRAM
A chart which places common occurrences in rank order.
P CHARTS
Charts used to plot percent defectives in a sample where sample size is variable.
PERTURBATION
A nonrandom disturbance.
POISSON DISTRIBUTION
A statistical distribution associated with attribute data (the number of non-continuities found in a unit) and can be used to predict first pass yield.
POPULATION
A group of similar items from which a sample is drawn. Often referred to as the universe.
POPULATION
The entire set of items from which a sample is drawn.
POWER OF AN EXPERIMENT
The probability of rejecting the null hypothesis when it is false and accepting the alternate hypothesis when it is true.
PRECISION TO TOLERANCE
A ratio used to express the portion of engineering
RATIO (P/T)
Specification consumed by the 99% confidence interval of measurement system repeatability and reproducibility error. (5.15 standard deviations of R&R error)
PREVENTION
The practice of eliminating unwanted variation before the fact, e.g., predicting a future condition from a control chart and then applying corrective action before the predicted event transpires.
PRIMARY CONTROL
The major independent variables used in the experiment.
No comments:
Post a Comment