Writing goals provide direction, help develop an action plan and provide motivation along the way. The act of writing the goals allows the person to fully develop the goals with a specific focus. The written goals serve as a reminder of goals and as a record as goals become reality.
A written goal puts an abstract wish or desire into action. Instead of just wishing to lose weight, the person gets specific with how to lose the weight and what type of measurement she'll use to gauge success.
Effective written goals are specific with measurable outcomes and a timeline for completion. An employee who wants to make herself more marketable might set a goal to complete an advanced college degree in three years. She has an end date that helps her stay on track. She measures her progress toward that goal by tracking the coursework as she completes it.
Posting a written goal serves as a motivator. The visual is a constant reminder of what the person wants to achieve. Without the reminder, it is easy to forget or ignore the goals, especially if they require hard work.
As a person grows and changes, her goals may also change. Looking back on her written goals helps her see how far she has come and decide how to proceed going forward.