This paper compares conceptual data models including extended entity relationship (EER), semantic object model (SOM), object role modeling (ORM), and object modeling technique (OMT) in term of model correctness, modeling time, and preceived ease-of-use. For an empirical study, 28 graduated and 72 undergraduates were selected and then divided into four equally sized groups. Each group was trained with one data modeling technique. Two cases were used; one was prepared in natural language and the other in enterprise form. The study results show some differences among the four conceptual data modeling techniques. These positive findings may help modelers better understand modeling techniques.