valikointivirheinä

Valikointivirheinä, a Finnish term, translates to "selection bias" in English. It refers to a systematic error that occurs in the selection of participants or data for a study. This bias arises when the sample used for analysis is not representative of the population from which it is drawn, leading to an over or underrepresentation of certain characteristics or outcomes.

There are several types of selection bias. For instance, survival bias occurs when only successful cases survive to be studied, ignoring failures. Volunteer bias arises when individuals who volunteer for a study are systematically different from those who do not. Attrition bias happens when participants drop out of a study unevenly, with those who drop out having different characteristics than those who remain.

Selection bias can significantly impact the validity and generalizability of research findings. If the selected sample is skewed, the conclusions drawn from the study may not accurately reflect the true situation in the broader population. This can lead to flawed decision-making in various fields, including medicine, social sciences, and business. Researchers strive to minimize selection bias through careful study design, random sampling techniques, and appropriate statistical methods to adjust for potential imbalances. Identifying and acknowledging the presence of selection bias is crucial for interpreting research results correctly.