description

Selection Bias is created when a person does a study that deliberately omits evidence that contradicts one particular outcome. A typical type of selection bias is a screening system for participants in a study or survey that rejects people that probably won't produce the desired result.

One special type of selection bias is confirmation bias.

examples

Many diet studies suffer from selection bias. They disqualify people who drop out. Most of the dropouts do so because they weren't losing weight.