Types of Bias

  • Reporting bias
    • Frequency of events/properties/outcomes in data set does not accurately reflect real-world frequency
    • e.g. People reporting unusual circumstances, ignoring the ordinary
  • Interaction bias
    • Algorithm biased due to the way users interact with it
  • Latent bias
    • Incorrectly identifying something based on historical data, or a preexisting stereotype in the data e.g. correlating “doctor” with men, because of stock imagery
  • Selection bias
    • Data not chosen in a way reflected of real-world distribution
    • Coverage bias—Data not selected in a representative fashion
    • Non-response bias—Unrepresentative due to participation gaps
    • Sampling bias—Proper randomization not used during data collection
  • Automation bias
    • Tendency to favour results generated by automated systems over those generated by non-automated systems
    • e.g. Favouring model when humans perform with better precision and recall
  • Group attribution bias
    • Tendency to generalize what is true of individuals to an entire group which they belong
    • In-group bias—A preference for members of a group to which you also belong
    • Out-group homogeneity bias—Stereotyping of members of groups to which you do not belong
  • Implicit bias
    • Assumptions made based on own mental models and personal experiences
    • Confirmation bias—Data processed in such a way that it affirms preexisting beliefs and hypotheses, e.g. keep training model until it produces result that aligns with original hypothesis

Affects

  • Affects entire pipeline
  • Can appear at every point of pipeline:
    • Collection
    • Labelling
    • Model
  • Check for use case using any of the following:
    • Biometrics
    • Race
    • Skin colour
    • Religion
    • Sexual orientation
    • Socioeconomic status
    • Income
    • Country
    • Location
    • Health
    • Language
    • Dialect
  • Also check for data likely to be correlated with the above, e.g. postcodes/zip codes etc. correlated with socioeconomic status and income

Evaluating Metrics with Inclusion

  • Look at performance of model across subgroups to ensure no unconscious bias
  • Use Confusion Matrix on subgroups (classification problems only)
  • Concentrate on false negative and false positive rates to see how adversely a subgroup is performing
  • Calculate e.g. Precision and Recall for subgroups
  • Example: whether to blur an image of a face on Street View - More false positives (annoying) vs more false negatives (PII issue)
  • Compare false positive and false negative rates across subgroups

Graph View