Judith Williamson was an author and professor who analyzed advertisements from a semiotic perspective in her 1978 book "Decoding Advertisements." She argued that advertisements create meanings and social differentiation to promote ideologies about gender, beauty, and social groups. While her analysis of advertisements from the 1970s is still relevant today, updating her research to include perspectives from real audiences could strengthen her arguments. Overall, her work fundamentally changed how media texts are analyzed and has continued influencing scholars through its insights into how advertisements construct meaning and shape society.