This chapter describes our research focused on deriving changing cognitive state information from the patterns of data acquired from the user, with the goal of using this information to improve the presentation of multimedia computer information. Detecting individual differences via performance and psychometric tools can be supplemented by using real-time physiological sensors. Described is an example computer task that demonstrates how cognitive load is manipulated. The different types of physiological and cognitive state measures are discussed along with their advantages and disadvantages. Experimental results from eye tracking and the pressures applied to a computer mouse are described in greater detail. Finally, adaptive information filtering is discussed as a model for using the physiological information to improve computer performance. Study results provide support that we can create effective ways to adapt to a person’s cognition in real time and thus facilitate real-world tasks.