Final answer:
An undefined time period is not a characteristic of effective goal setting because goals should be time-bound to prompt timely action and set a clear deadline.
Step-by-step explanation:
The characteristic of effective goal setting that is not accurate is D. Undefined Time Period. Effective goal setting requires goals to be time-bound, meaning they have a specific target date or deadline. The attributes of effective goals can be summarized by the SMART acronym, which stands for Specific, Measurable, Achievable, Relevant, and Time-bound. A goal with an undefined time period lacks the 'T' element of the SMART criteria, and thus produces a less effective goal setting process because it does not prompt timely action or give a clear deadline to work towards.