Scale Analysis

The Experience Sampling Method (ESM-34) was developed in 1995 by P. Delespaul and represents an effort to provide a valid means for describing variations in self-reported mental processes. The questionnaire covers current mood, cognition, perceptions, behaviors, and situational descriptions (e.g., location, company, activity). The ESM is useful in psychiatry as well as in patients with physical illnesses.

Scale Objective

The Experience Sampling Method is a research procedure designed to study what people do, feel, and think during their everyday lives. The method focuses on both symptoms (poor health) and adaptive functioning (well-being), aiming to capture normal daily psychological functioning. Initially, paper diaries were used in combination with pagers or electronic wristwatches. With technological advancement, data collection improved through the use of personal digital assistants (PDAs) and electronic applications.

Question Calibration

Participants are asked to complete a morning and an afternoon questionnaire during their day, prompted by sound notifications received on their PDAs. The questionnaire consists of 34 items related to the participants’ emotions at the moment of completion, answered on a 7-point Likert scale ranging from 1 (Not at all) to 7 (Very much).

Statistical Analysis

The questionnaire produces a total score by summing the points from all items, with a possible range from 34 to 238. Higher scores indicate that the individual is dissatisfied with daily life and experiences either physical or psychological difficulties.

Validity and Reliability

The questionnaire has been adapted into Greek by G. A. Floridou and translated through the back-translation process. It demonstrates excellent internal consistency. Correlations between symptoms were estimated using a regression model for each pair of symptoms. Since measurements for each participant are repeated across different time points and the data include unequal sample sizes due to missing values for specific times, a Generalized Estimating Equations (GEE) adjustment is applied to the regression model to estimate the correlations.

Bibliography

Author: P. Delespaul (1995)
Greek adaptation: G. A. Floridou
Delespaul, P. (1995). Assessing schizophrenia in daily life: The experience sampling method.