California is known for having some of the most employee-friendly laws in the country, giving employees more protections in the workplace than they would have in nearly any other state. Despite this, gender discrimination is still a common occurrence at the office, particularly with respect to salary.

Women working in Silicon Valley often say that they are not treated as well as their male counterparts who dominate the tech industry. However, demonstrating that a female employee is paid less than a male employee can sometimes be a challenge, particularly if the employer can point to differences in skill or education that supposedly justify a pay differential. These challenges make a recent victory in San Mateo Superior Court particularly notable where three female plaintiffs just obtained class certification for over 4,000 female employees of Oracle Corp.

On a class certification motion, plaintiffs must show that their claims against the defendant are typical of the individuals in the class that they seek to represent. Plaintiffs also have to show that they are adequate representatives of the class, that their claims present questions of law or fact common among the class, and that it would be impracticable for the class members to bring their own individual claims separately. Plaintiffs here relied on a survey of Oracle employees showing that women were paid 13% less than men; Oracle unsuccessfully tried to exclude the study from consideration. Plaintiffs also relied on an argument that they were tagged with the same job codes and performed the same work as men receiving higher pay.

Many workplace discrimination claims do not proceed on a class-action basis, making it easier to establish a plaintiff’s damages. If an employee feels that he or she has been discriminated against based on age or any other basis, that person may want to consult with a plaintiff-side employment law attorney.