Final answer:
An operational definition should ideally include positive terms that provide a clear and specific description of the behavior being measured.
Step-by-step explanation:
An operational definition should ideally include positive terms. It is important to use language that clearly describes the behavior or concept being measured in a positive way. For example, instead of using a negative term like 'not disruptive', it would be better to define the behavior as 'actively engaged in learning'. This provides a clear and specific description of the behavior.