Read these paragraphs. A police officer’s primary duty is to protect the lives and property of others. In order to become a police officer, a high school diploma or its equivalent is required. Additionally, most must also graduate from their agency’s training academy and fulfill difficult personal and physical qualifications, as well. In 2010, police officers in the United States earned a median yearly income of approximately $55,000. Unfortunately, there is a high rate of on-the-job injuries for police officers. A judge is responsible for applying the law in court and overseeing the legal process. One of the major duties of a judge is to help negotiate agreements between opposing parties. Most judges are elected or appointed, and they are typically required to have a law degree and to have worked as a lawyer. The average median yearly salary for judges in 2010 was $92,000. Both of these careers are a part of the legal system. Similarly, both require specialized training before a job can be obtained. However, it takes much longer to become a judge than it does a police officer, and a judge can expect to make more money. Although they are both trained to uphold the law, the role each plays in the legal system is very different. What makes these paragraphs an example of subject-by-subject writing? The paragraphs focus more on what is involved in becoming a judge as opposed to becoming a police officer. The paragraphs focus first on becoming a police officer, second on becoming a judge, and finally on comparing the two. The paragraphs compare two different careers, discussing criteria about each career one point at a time. The paragraphs look at a variety of criteria involved in becoming a judge and a police officer, including salaries and the risk of on-the-job injuries.