Design of Experiments

Tutorials on Design of Experiments (Multivariate Analysis)

 

I’ll be posting video tutorials here.

 

DOE Vocabulary

Effect – The change in the response variable that occurs as a factor is changed from one level to another

Factor – A controlled or uncontrolled input variable

Fractional Factorial DOE – Looks at only a fraction of all the possible combinations contained in a full factorial. If many factors are being investigated information can be obtained with smaller investment. The general notation for a fractional factorial design is:  2Rk-p = # Runs

Full Factorial DOE – Full factorials examine every possible combination of factors at the levels tested. The full factorial design is an experimental strategy that allows us to answer most questions completely. The general notation for a full factorial design is:  2k = # Runs

Level – A specific value or setting of a factor

Interaction – Occurs when the effect of one factor on the response depends on the setting of another factor

Randomization – A technique used to spread the effect of nuisance variables across the entire experimental region. Use of random numbers to determine the order of the experimental runs or the assignment of experimental units to the different factor-level combinations

Repetition – Running several samples during one experimental setup run

Replication – Replicating (duplicating) the entire experiment in a time sequence

Resolution – of a design is a value such as III, IV, V, etc., that represents the type of confounding for that design.

Response Variable – An output which is measured or observed