Recently, my friend Jason asked me a question: “What do you think makes HCI different from Psychology?” I hadn’t really thought about it before, as I naturally considered them two distinct domains. But when asked to explain the difference in just a few minutes, I found myself at a loss for words. This got me thinking more deeply about what makes HCI unique from other disciplines.
At first glance, both fields seem to have a lot in common, as they’re both centered around understanding humans. In fact, HCI couldn’t exist without drawing from the theories and insights developed in psychology. Psychology delves deeply into aspects like cognition, emotions, and behavior, while HCI often borrows these insights to improve user experiences, to design systems and technologies that align with how people think and behave.
Where the two fields start to differ is in how they approach technology. Psychology tends to use technology as a tool, for instance, to develop applications that help treat anxiety or other mental health conditions. The core focus of psychology remains on how these tools influence mental states and behaviors.
HCI, by contrast, places the interaction between humans and technology at the forefront. It’s not just about how technology impacts people; it’s about how people engage with technology—whether through apps, websites, or devices—and how those interactions are designed. For example, in HCI, we spend a lot of time thinking about things like notification frequency, user interface intuitiveness, and how such design choices affect user behavior and experience.
This emphasis on interaction has led to a substantial body of research in HCI, aimed at understanding how specific design choices shape user behavior. The resulting knowledge from empirical studies that future researchers can build upon to figure out which design considerations lead to certain outcomes. This is a core part of what makes HCI unique.
Based on the revealed empirical knowledge, two key directions in HCI have emerged. First, HCI explores how new technologies can enable different or improved ways for humans to interact with computers. For example, Siri started out as a simple voice assistant, but with advances in natural language processing, particularly with large language models (LLMs), we now have the potential to create much more capable systems. Second, HCI examines whether design principles from older technologies still hold up when new ones are introduced. For instance, design principles that work for e-learning interfaces on 2D screens might not apply as effectively in virtual or augmented reality (VR/AR). If not, the new interaction paradigms may be needed, changing how we approach design in those contexts.
These two directions continuously generate new empirical knowledge about the design and study of interactions between people and technology, further advancing the HCI field different from others.