Group differences, people, machines, and instruments can all introduce what into the results?

Group differences, people, machines, and instruments can all introduce what into the results?

• A. Bias
• B. Random error
• C. Systematic error
• D. They can introduce error

Answer: (D)

The key idea is that measurements and results can be shifted away from the truth by factors in the study. Group differences, people, machines, and instruments can all introduce deviations in the data. These aren’t just occasional hiccups—they’re sources of error that can affect the accuracy of findings. Some of these effects are systematic, pushing results in a consistent direction (bias or systematic error), while others contribute to random variation. Because “error” covers all of these possible deviations, stating that they can introduce error is the most inclusive and appropriate answer. In practice, researchers try to minimize error through careful design, calibration, and standardized procedures.

The key idea is that measurements and results can be shifted away from the truth by factors in the study. Group differences, people, machines, and instruments can all introduce deviations in the data. These aren’t just occasional hiccups—they’re sources of error that can affect the accuracy of findings. Some of these effects are systematic, pushing results in a consistent direction (bias or systematic error), while others contribute to random variation. Because “error” covers all of these possible deviations, stating that they can introduce error is the most inclusive and appropriate answer. In practice, researchers try to minimize error through careful design, calibration, and standardized procedures.