Final answer:
Diagnostic evaluations are used to identify where results deviate from planned levels and locate specific problem areas. They contrast with formative, summative, and norm-referenced evaluations. In addition, a measurement is considered valid when it accurately measures what it's supposed to measure.
Step-by-step explanation:
Evaluations are essential tools in business and education used to assess various aspects of performance. The type of evaluation described in the question, which identifies areas where results are above or below planned levels and pinpoints problem areas, is a diagnostic evaluation. This form of evaluation is crucial for understanding specific issues or challenges that may be affecting performance or outcome and allows for targeted interventions.
In contrast, formative evaluations are used during the process to monitor progress and inform ongoing improvements, summative evaluations are conducted at the end of a process to assess overall effectiveness, and norm-referenced evaluations compare performance against a standard norm group. Regarding the secondary question, a measurement is considered valid if it accurately measures what it is intended to measure, which is crucial for the reliability of the results obtained from any type of assessment or research.