In the Rising Tide expansion, I can acquire Artifacts by performing Expeditions, pillaging Alien Nests, and finding them in resource pods. If I research three artifacts at once, they provide a bonus effect in addition to the normal production/science/culture yield. This bonus effect is either a civilization-wide effect, or a new building.
However, when I swap different types of artifacts to research, the bonus I unlock doesn't seem to change. How is it affected by the types or quality of the artifacts I research?