A student sets a goal to improve a weakness but does not define how progress will be measured. What is the main gap?

Correct answer: Evidence of improvement and review criteria are unclear

A goal gives direction, but without a measurement method the student cannot tell whether improvement is occurring or whether the strategy needs changing. A useful plan should state an observable indicator, a time period and a review point, such as completing a defined number of practice tasks accurately. The goal itself may be valuable; the missing element is evidence and criteria. Thus, D is correct.