Development of a practical tool for analysis of data obtained by factorial design 22 e 23 using the software microsoft office excel®2007 (microsoft corporation, EUA)

Resumo

The factorial design is an important statistical tool, which due to its simplicity is being increasingly used for different samples and purposes. This increasing use is justified by the allowance of results’ interpretation considering all experimental parameters involved, in addition to provide the effects of possible interactions between the selected variables. The mathematical expressions used for the required calculations in the evaluation of the data obtained are widely presented in the literature and this study aimed to produce a practical tool that can assist the execution of these calculations in a fast and simple way. Spread sheets were produced for the analysis of the obtained data by factorial design 2² and 2³ using the software MICROSOFT OFFICE EXCEL®2007 (MICROSOFT CORPORATION, USA). With this tool, it is possible, from the data obtained through factorial design assays, to quickly obtain the values ​​of the each factor’s effects on the response being studied, as well as their interactions, also assessing the statistical significance of each one about the response in question. It is noteworthy that the direct use of 'friendly' softwares without first knowing the methodology’s fundaments, can lead users to dangerous misinterpretations. Therefore, it is recommended to previously understand the fundamentals of the methodology and the importance of performing each step in the procedures’ implementation.