Project Summary Under the renewal of the Mobile Toolbox (MTB2), the Project and Cores will work collaboratively to enhance the Mobile Toolbox (MTB) platform so that it may become a form of “common currency” for remote assessments with the flexibility to meet the needs of researchers across a vast array of diverse study designs and populations. To accomplish this, the Project will develop, integrate, and psychometrically evaluate new measures and retention strategies that will benefit future research utilizing remote assessment tools. The primary aims of the Project include: Aim 1: Identify, develop, and integrate non-cognitive measures and passive sensor technology for the Mobile Toolbox (MTB) to enable the collection of lifespan contextual, psychological, physical, and behavioral experiences to enhance the assessment of cognitive trajectories; Aim 2: Evaluate the psychometric properties of the MTB2 measures through a series of data collection protocols aimed at calibration, norming, validation, and measurement sensitivity; and Aim 3: Leverage longitudinal studies included in MTB2 to develop, integrate, and evaluate retention strategies to improve participant adherence and compliance. The measures introduced by MTB2 will be designed around the technical specifications of an open software iOS and Android platform that enables external researchers to customize a mobile app to fit their study needs. Researchers will be able to choose from a diverse selection of measures, including several change-sensitive cognitive tasks, measures of contextual and exposure variables, as well as physical, behavioral, and psychological functions. We will then calibrate new measures using Item Response Theory by administering them to a large general population sample. All newly developed measures will be validated against existing gold standards in a sample of healthy adults ages 20-85 with a 7- to 21-day retest; MTB measures will be completed in an un-proctored setting. We will also conduct a clinical validation study and identify normative values for the new MTB measures using a large, nationally representative sample. Finally, a series of hypothesis-driven studies prioritized by the NIH, Steering Committee, and External Scientific Panel will be used to explore the relationship between non-cognitive and cognitive functions across the adult lifespan. By leveraging the MTB2 longitudinal studies, we will identify dynamic motivational strategies that help sustain participant engagement, promote re-engagement, and maintain long-term study adherence. MTB2's range of evidence-based incentive strategies at both the group and person-centered level will be integrated into the researcher study portal to allow studies with diverse cross-study designs and assessment schedules to maximize engagement and retention. Special attention will be paid to retaining participants from minority health and NIH-designated populations that experience health disparities.