Estudo das relações entre variáveis segundo análises de moderação e mediação (Examining relationships between variables through moderation and mediation analyses)

Empirical evidence-based practice has increasingly become a requirement in professional settings. Within this context, psychological research plays a pivotal role in society, providing insights that guide psychologists across various domains. These findings help identify interventions with a higher likelihood of success, whether for individuals or groups, or organizational strategies to foster greater employee engagement.For instance, consider investigating whether the number of hours children spend on violent games impacts their levels of aggressiveness at school. This poses a valuable research question. Similarly, we might explore whether the time children spend on homework influences academic performance. In both cases, a simple linear regression analysis could be used to assess how the independent variable (hours spent on violent games or homework) predicts the dependent variable (aggressiveness or academic performance). However, concluding that aggressiveness or academic performance depends on a single predictor may be overly simplistic, prompting us to consider multiple predictors using multiple linear regression analysis.The real world, however, is inherently complex, and human behavior is influenced by multiple factors. This complexity raises the question of whether the predictions for aggressiveness or academic performance are influenced by other characteristics of the environment or the children themselves. For example, building on scientific literature and prior empirical studies, we might hypothesize that the relationship between violent games and school aggressiveness differs by gender. Suppose we predict a weak association between hours spent on violent games and aggressiveness for girls, but a strong association for boys. In this scenario, the variable "student gender" would moderate the relationship between violent games and aggressiveness. To investigate such moderating effects within subgroups (e.g., boys and girls), a moderation analysis is required. This approach is a key focus of the present chapter.