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MANE 6313

Week 7, Module D

Student Learning Outcome

  • Select an appropriate experimental design with one or more factors,
  • Select an appropriate model with one or more factors,
  • Evaluate statistical analyses of experimental designs,
  • Assess the model adequacy of any experimental design, and
  • Interpret model results.

Module Learning Outcome

Describe single replicate of 2k factorial designs

Resources for the Week 7, Module D micro-lecture are:


Single Replicate of \(2^k\)

  • Revisiting. Main problem is no estimate of error

  • Very common occurrence because replicated experiments are expensive.

  • Two approaches to analyzing an unreplicated \(2^k\) design

    • Scarcity of effect principles assumes that higher order interactions do not exist. These effects are combined to estimate the SS(error).

    • Normal probability plot approach


Probability Plot Approach

  • Recommended by Daniel (1959)

  • Generate a normal probability plot for the effect estimates

  • For non-significant effect, they will have zero mean and variance \(\sigma^2\). Thus, they will graph as a straight line on normal probability plot.

  • Significant effects will have a non-zero mean and lie along a straight line in the normal probability plot


Design Projection

  • Hopefully some variables can be discarded from the initial model.

  • Whenever a variable is removed from an unreplicated design the resulting design (in fewer variables) is replicated.

  • Very useful property that we will use later in the course


Diagnostics

  • The usual diagnostics (residual) analysis should be applied in an unreplicated design