Final answer:
The discrepancy when two therapists measure different values on the same patient is referred to as poor interrater reliability, which is crucial for ensuring consistent and credible data.
Step-by-step explanation:
The term used when two therapists measure drastically different values on the same patient is known as poor interrater reliability. Interrater reliability refers to the level of agreement between two or more raters or observers. In a healthcare or research context, if different therapists or evaluators are obtaining significantly different measurements or assessments on the same patient, it indicates that there's a lack of consistency between the raters, which can impact the credibility and usability of the data collected.
It is crucial for reliability that different raters can produce the same results under the same conditions. Factors that could affect interrater reliability include the skill of the person making the measurement, limitations of the measuring device, and irregularities in the object being measured. These discrepancies need to be addressed to ensure that the evaluations are reliable and can be used confidently for patient assessment or research purposes.