ABSTRACT
II. Full factorial designs at 2 levels The 22 design - example of extrusion-spheronization Full factorial design for 3 factors (23) - formulation of an oral solution Full factorial design for 4 factors (24) - a mixture example Identifying active factors in saturated designs General forms of full factorial designs and their mathematical models
III. Fractional factorial designs Partition of the (full) factorial design Double partition of a complete factorial design Generalisation: the construction and properties of fractional factorial designs Continuation or complement to a fractional factorial design Factorial designs corresponding to a particular model
IV. Time trends and blocking Effect of time (time trend) Block effects
V. Other designs for factor studies % designs Rechtschaffner designs D-optimal designs Conclusion
I. INTRODUCTION
A. The Place of a Factor Study in Development
We have now covered the standard methods used for screening studies, which, carried out early in a project's lifetime, consume only a small part of the resources of time, money, materials, availability of equipment, etc... allocated to it. We may therefore suppose that, having completed such a study, we are left with rather fewer factors and are thus ready to carry out a detailed quantitative study of the influence of these factors. In fact, a separate screening study is only justified if there are many factors and not all are expected to be influential.
