- Each experiment run is a test.
- An experiment is a series of runs in which changes are made to the input variables of a process or system.
- An experiment objective is to determine the influence that misc factors have on the output response of the system.
- The general approach to planning and conducting an experiment is called the strategy of experimentation.
- Best-Guess Approach
- One-Factor-at-a-Time (OFAT)
- The OFAT method consists of selecting a starting point or baseline set of levels for each factor, and then successively varying each factor over its range with the other factors held constant at the baseline level.
- The major disadvantage of the OFAT strategy is that it fails to consider any possible interaction between the factors.
- Factorial Experiment
- The correct approach to dealing with several factors is to conduct a factorial experiment.
- This is an experimental strategy in which factors are varied together, instead of one at a time.
- Each factor (combination) can be replicated in an experiment design.
- Fractional Factorial Experiment: a variation of the basic factorial de# which only a subset of the runs is used.
- Experiment Design
- The three basic principles of experimental design are randomization, replication, and blocking.
Sometimes we add the factorial principle to these three.
- Randomization refers to the allocation of the experimental material and the order of individual runs of the experiment to be determined randomly.
- Replication refers to an independent repeat run of each factor combination.
- Blocking is a design technique to improve the precision with which comparisons among the factors of interest are made.
- Often blocking is used to reduce or eliminate the variability transmitted from nuisance factors.
- A block is a set of relatively homogeneous experimental conditions.
- Each level of the nuisance factor becomes a block.
- Then the experimenter divides the observations from the statistical de#to groups that are run in each block.
- The three basic principles of experimental design are randomization, replication, and blocking.
Sometimes we add the factorial principle to these three.
- Recognition of and statement of the problem
- Factor screening or characterization
- Optimization
- Confirmation
- Discovery
- Robustness
- Selection of the response variable
- Choice of factors, levels, and range
- Choice of experimental design
- Performing the experiment
- Statistical analysis of the data
- Conclusions and recommendations
- Random Variables
- Discrete
- Continuous
- Regression Analysis
- Linear Regression Models
- Non-Linear Regression Models
- Survival Analysis
- Non-Parametric Models
- Parametric Models