3 Process Characterization

  • Tools
    • Validation
      • Fit for purpose - comparison to gold standard method or reference material
        • no gold standard methods - only community accepted defactor standards
    • Benchmarking
      • Comparison to known truth
      • Evaluating results based on expectation
    • Robustness testing
      • Impact of procedure or step on results
  • Characterization of Data Analysis Processing
    • Wet lab vs. dry lab
    • Validation
      • Currently not applicable … -> most robust method
    • Benchmarking
      • Observed results vs. Truth
        • Dataset with known true value - can be obtained using
          • gold standard method
          • mock communities: in vitro or in silico
            • limitations and assumptions
          • Mixtures
            • Provides a degree of known truth
        • Performance metrics
          • Quantitative
            • Variability - standard deviation/ variance
            • Bias - mean squared error??? (true value)
      • Observed results vs. assumptions
        • No general dataset requirements
        • Performance metrics
          • evaluate results based on method assumption, e.g. Schloss clustering distance
    • Robustness Testing
      • Used to evaluate impact of different methods on results
      • Comparison of orthogonal methods
        • For fundamentally different methods (different assumptions and heuristics)
          • Can evaluate precision (variability), not necessarily accuracy but less susceptible to bias than is methods are based on the same assumptions or heuristics
      • Used to evaluate how different steps in the process affect the results