It clearly identifies the relationship that is going to be investigated.
The variables of interest are specified.
It identifies the population measured in the given dataset.
It identifies what the relationship is going to predict.
Think about the population of the related issue. Can the results be extended to a wider population?
NB The source of the data should be stated
The better your question the better your investigation will be!
I am going to investigate the relationship between sum of skin folds and percentage body fat in Australian athletes for the purpose of predicting the percentage body fat for Year 13 students in New Zealand.
I am going to investigate the relationship between the mean daily temperature and mean minimum daily temperature in New Zealand for the purpose of predicting the mean minimum daily temperature for given locations in the North Island.
I am going to investigate the relationship between red blood cell count and weight in Australian athletes for the purpose of predicting red blood cell count for athletes in New Zealand.