Introduction to simulating Cronbach's alpha values ​​using the simAlpha© algorithm

A questionnaire is a structured tool used in health research to systematically collect data on perceptions, behaviors, and health outcomes. It serves as a fundamental tool for recording patient-reported outcomes, evaluating treatment effectiveness, and monitoring public health trends. Questionnaires can be administered in a variety of formats, including paper, digital, or interactive systems, and must be carefully designed to ensure reliability, validity, and minimal bias. The simAlpha algorithm was designed in 2023 by Basispap to simulate Cronbach's Alpha and uses R code for its implementation. It has been used professionally in several cases where a simulated study of Cronbach's alpha was needed. In addition, it can provide specific mean values of the Likert scale before the study, as well as the number of participants on demand. It is a useful tool for reducing the time of collecting comparative data e.g. in a pilot study. A brief presentation of the algorithm as well as its strengths and weaknesses is presented. The simulation results show improved behavior for a large number of simulated participants and repetitions (N > 100,000), but the number of simulated questions remains satisfactory even in the case of small numbers, such as e.g. 10 questions. The flexibility of the algorithm needs to be improved for alpha values lower than 0.7. This means that an inexperienced user may have difficulty performing simulations for desired alpha values lower than 0.7, although a more experienced user can easily adjust the desired alpha to obtain the exact required value.

Keywords: Cronbach’s Alpha ; Simulation ; simAlpha