background  Humans are continuously interacting with the world. However, the interaction between the person and the environment is not much investigated in contemporary psychoses research. ESM is a structured diary technique assessing thoughts, mood, psychiatric symptoms, and contexts in daily life.
aims  To discuss the importance of the Experience Sampling Method (ESM) for the study of subjects with psychoses in their daily life.
method  A Medline search was conducted using as key words 'schizophrenia', 'psychosis' and 'experience sampling method'.
result  ESM has been proven useful for the refinement of the phenomenology and dynamics of psychotic symptoms, for the investigation of aetiological mechanisms underlying psychosis, and in support of therapeutic activities in clinical practice.
conclusions  Instruments such as esm are valuable because they deepen our scientific knowledge with data from real life.