A systematic error that biases results in a particular direction is called ...

• A. Bias
• B. Sampling
• C. Reliability
• D. Validity

Answer: (A)

Systematic error that consistently pushes results in one direction is called bias. In research, bias means the measurement or procedure introduces a consistent distortion, so the average result shifts away from the true value in a specific way. This is different from random errors, which bounce around without a predictable direction.

Reliability is about how consistently you get the same results across repeated trials, not about whether those results are accurate. Validity concerns whether you are actually measuring what you intend to measure. Sampling relates to how you select participants or data points; a biased sample can create skew, which is one source of bias. For example, a thermometer that always reads 1 degree too high will give measurements that are systematically higher, illustrating a directional bias.