The quality of an art or craft is not only a subjective notion. The authenticity, adhesion to stylistic norms and mastery of used materials have to be considered .
Authenticity means that the object was crafted in a traditional environment and for ordinary use.
Adhesion to stylistic norms , personal improvisation of creators being limited by a necessary identification of shapes and symbols, corresponds to the instrumental role of ritual objects where aesthetic emotion is intimately linked with social and metaphysical considerations. In the Libreville Museum, the mahongu , galoa and tsogho are interesting to see as particularly successful pieces, but also as the keys to a complex cultural worlds. Social life, rites and beliefs Social and political structures did not go beyond the village. Migrations were not mass movements but small successive moves, more or less concerned with neighbor relations. This is essential to the understanding of the cultural diffusion process of certain rituals and symbolic motives, or even objects.