The court will have to be persuaded that the following 4 things have been proved before it certifies a class action:
1. The class is so numerous, that individual lawsuits could not be filed and joined together. That usually means that there must be at least 40 people that are similarly situated.
2. There are common questions of fact or law, which means that all the class members have suffered a similar wrong, and proving that wrong would involve proving similar facts and using similar law.
3. The claim of the plaintiff is typical of all the class members’ claims. In other words, the plaintiff and the class have suffered from a similar wrongdoing, and the plaintiff’s claim is not unusual as compared to the claims of the class members.
4. Plaintiff and class counsel are qualified to and will protect the interests of the class members.