Integrating Intensity Scaling Into Consumer Free Listing to Describe the Sensory Attributes of Potato Chips

Abstract

This study aimed to introduce a consumer-based sensory evaluation method, Free Listing with Scale (FLS), grounded in a cognitive psychology framework suggesting that analytical processing enhances the discrimination of sensory attributes. The study also sought to conduct a methodological comparison between FLS and conventional free listing (CFL). Six commercial potato chip samples were evaluated by a trained panel (n = 8) using descriptive analysis (DA) and by untrained consumers (n = 250; 125 per method) using CFL or FLS. In FLS, participants described perceived sensory attributes and rated their intensities (“weak,” “moderate,” or “strong”). Text analysis and Smith's salience index (SSI) were used to extract and quantify sensory terms. Across all samples, FLS identified 14 significant sensory attributes and showed a greater number of attributes exhibiting trends consistent with DA compared to CFL (CFL = 9; FLS = 13). SSI values and SSI-based principal component analysis (PCA) indicated that both methods produced generally comparable sensory configurations; however, FLS enhanced perceptual sensitivity, enabling the identification of more sensory attribute terms (CFL = 8; FLS = 10). Based on SSI and 1000 bootstrap iterations, 145 (CFL) and 135 (FLS) consumers were required to achieve RV = 0.95, whereas 220 (CFL) and 170 (FLS) were needed for RV = 0.99. These findings suggest that incorporating intensity scaling into free listing improves consumers' discrimination of sensory differences and yields more stable data than frequency-based approaches alone. By bridging qualitative consumer input with quantitative DA outcomes, FLS offers a time- and cost-efficient method for industrial and consumer-oriented sensory research.