Uncertain goals should be set in the middle. This will enable you to set the correct challenge level to maximize effort.
Some research shows that for very complex tasks, goal-setting can hinder effectiveness. This is because complex tasks are cognitively demanding in the beginning and can be frustrating because you can't perform adequately. To add on more tasks can impair your performance.
Whenever you set a goal, create a new habit or make some plan for your life, there's a few different ways you can go about it The first way is to target the minimum output. The idea here is that you focus on always doing at least a little bit, so that overall, you'll end up doing enough to make it count.
Minimum targeting works well for establishing long-term habits.
A goal of, for instance, doing fifty push-ups every day might not be ideal for fitness, but doing something is better than doing nothing.
Another reason to focus on the minimum is that it assumes the difficulty is in starting. To start a process can often be the hardest. Then you want to set a lower threshold to make starting as easy as possible.
Setting personal goals is not some kind of magic that will immediately make all your dreams come true. Of course, personal goals require commitment and action. But they have a tremendous power to give meaning to a daily routine and transform your life to the better.