- Cognitive Bias
Also referred to as Expectation Bias or Observer-Expectancy Effect.
A subset of Confirmation Bias, Expectation Bias is the tendency for a researcher to mainly use data that matches their expectations for the project and to disregard data that conflicts with their expectations. Anytime a researcher removes “unexpected” or outlier data, potentially there is experimenter’s bias at play.
Common Types of Experimenters Bias
- Design: During the design of an experiment, a researcher may form a hypothesis and base their research methodology around their expectations.
- Sampling: Choosing participants in a manner that under or over represents certain demographics.
- Procedural: The way the researcher carries out studies influences the results.
- Interviewer: The way questions are asked or how they are phrased affects how participants answer them.
- Reporting: Presenting the research results in a manner that skews outcomes in the report.
Examples of Experimenters Bias for researchers
- A researcher filtering participants based on preconceived or personal biases.
- Product use cases planned around geographical location (ie, urban vs rural, San Francisco, etc).
- During research, an experimenter may inadvertently introduce bias through interview question phrasing.