A laboratory study comparing relational representations developed using the Data Aggregation approach with the Logical Relational Design Methodology (LRDM) was conducted to investigate whether non-expert users could better comprehend and apply either methodology. While no significant differences between user performance were noted, the study did find that subjects following the LRDM produced quality Entity-Relationship (ER) representations, but there was a marked deterioration of the translation to the relational form. The Data Aggregation solutions were generally poor in quality. The study concludes that while non-expert designers can produce acceptable data abstractions using a conceptual modeling methodology (e.g., ER diagrams), problems may arise during conversion to normalized relations (e.g., relational representations).