Question

which two characteristics of data always occur together?
○ high accuracy and high precision
○ high precision and good validity
○ low accuracy and low precision
○ low accuracy and good validity

Explanation:

• High accuracy and high precision: High accuracy means data is close to the true value, and high precision means data points are close to each other. These don't always occur together (e.g., precise but inaccurate measurements).
• High precision and good validity: Precision is about consistency, validity is about measuring what's intended. They aren't inherently linked to always occur together.
• Low accuracy and low precision: If data is low in accuracy (far from true value) and low in precision (data points are scattered), these often occur together. Inaccurate data that's also inconsistent (low precision) is common as both relate to errors in measurement or data collection.
• Low accuracy and good validity: Validity is about the measure being appropriate for the concept. Low accuracy (wrong value) and good validity (measuring the right thing) are contradictory—if it's valid, it should be accurate for the intended concept.

Answer:

C. low accuracy and low precision