This article presents a new methodological framework for multimodal observation of digital technologies. It is based on the use of mixed methods developed in the interdisciplinary MAN project founded by CNRS. It focuses on the digital accessibility of older people. The originality of the method lies in the implementation of a method combining qualitative and quantitative measurement to determine relevant indicators. These indicators characterize the person's behavior when using a technology and its usability. We show how these indicators are built, based on the cross-referencing of data. We present the different tools (questionnaire, interviews and technological data recording tools) used in the MAN method in a living laboratory environment controlled with four volunteers. Two use scenarios are proposed to illustrate the method in assessing the accessibility of a tactile application for older people without a digital divide and without disabilities. We present the recorded qualitative and quantitative data and illustrate by an example the unrelatedness of these data through a specific annotation tool.