A new climate externalities food knowledge test validated by item response theory and behavioural data prediction (Validación de una nueva prueba de conocimientos sobre la externalidad climática de los alimentos mediante la teoría de respuesta al ítem y la predicción a partir de datos conductuales)

Abstract

ABSTRACT Research underscores the imperative for global dietary shifts to curb global temperature rise within the Paris Agreement’s 2°C limit. Understanding human dietary behaviour is crucial for effective environmental policies promoting pro-environmental actions. A significant obstacle is the lack of awareness regarding the CO2 implications of meat and dairy consumption, hindering sustainable diet adoption. Thus, evaluating knowledge-based interventions requires reliable tools to quantify climate impact knowledge related to food consumption. Unfortunately, existing pro-environmental knowledge measurement instruments lack domain specificity, leaving a void in assessing climate-conscious food choice knowledge. Addressing this void, our climate externalities food knowledge test was developed. It underwent calibration via item response theory with a German university student sample and validation across one German and two Chilean student samples. The resulting scale exhibited a strong approximate model fit, acceptable item fit metrics, good reliability and the ability to predict climate-relevant food-choice patterns and expert group performance. However, notable differential item functioning was observed based on cultural context. Our instrument provides a valuable contribution to understanding and promoting sustainable food choices on a global scale.