Microbiology-PTM-OMA_Modules_1-5

Analyzing Data – Quantitative Methods

• Unblind the data • Analyze each level of each matrix separately • Perform a logarithmic transformation on the reported CFU/g or  CFU/mL: Log 10 [CFU/g + (0.1)f]  Where f is the reported CFU/unit corresponding to the smallest reportable  result and unit is the reported unit of measure (e.g., g, mL, in 2 , etc.).  • Perform outlier tests (Cochran and Grubbs) to identify significantly  outlying data points.  Data points may only be removed, however, for  justifiable cause.