A. Describe key features of the two types of bias and give examples of each:

1. Selection Bias
   • Define selection bias
   • Describe types of selection bias
     1. Control-selection bias
     2. Self-selection bias
     3. Loss to follow-up
     4. Differential surveillance, diagnosis or referral bias

1. Observation/Information Bias:
   • Define observation bias
   • Describe types of observation bias
     1. Recall bias
     2. Interviewer bias
     3. Differential and non-differential misclassification

B. Identify types of biases specific for different study designs:

1. Randomized clinical trials (RCT)
2. Case-control studies
3. Cohort studies

C. Understand how the magnitude and direction of bias can affect study results

D. Describe ways to minimize bias in the design phase of a study:

1. Develop an explicit case definition
2. Enroll all cases in a defined time and region from a defined source population
3. Strive for high participation rate (minimize loss to follow-up and drop-out rate)
4. Take precautions to ensure your sample is a good representation of the underlying population
5. Handling of misclassification (observer bias, measurement bias)
6. Other methods