Verzerrung (Bias)

Bias in research refers to systematic errors that favor or oppose a hypothesis. It can occur intentionally or unintentionally during data collection, analysis, interpretation, or publication phases. Understanding where bias enters the research process is essential for designing rigorous studies and drawing valid conclusions from data.

Sampling bias occurs when samples are non-randomly drawn from a population, making them unrepresentative. For example, predicting election outcomes using survey responses from only one political party introduces bias. This leads to incorrect conclusions about the entire population being studied.

Observer bias, also called research bias, occurs when a researcher's preconceived notions, expectations, or incomplete knowledge influences study results and their interpretation. This subjective influence can skew findings even when data collection procedures are technically sound. Recognizing this bias is critical for maintaining research objectivity.

Measurement bias occurs when poorly calibrated or faulty measuring instruments are used in experiments. Inaccurate equipment introduces systematic errors into data collection, compromising the validity of results regardless of proper study design or sampling methods. Regular instrument calibration helps minimize this type of error.

Publication bias occurs when research studies reporting statistically significant positive findings are more likely to be published than those reporting negative results. This creates a skewed scientific literature that overrepresents successful outcomes and may mislead future research directions and funding priorities.

Coins or dice can be biased when their physical properties are unequal. For example, a Belgian Euro coin showed 56% heads in 250 trials, suggesting unfairness. Casino dice are specially manufactured with flat faces and paint-filled holes of equal density to ensure each outcome is equally likely.

Funding bias occurs when researchers skew data to show outcomes favoring the funding body. This financial incentive can compromise research integrity by encouraging selective reporting or interpretation of results that align with the funder's interests rather than objective findings. Transparency about funding sources helps mitigate this risk.