To arouse the sentiments is as important for the success of a folkways presentation as anthropological accuracy. The value of what the Smithsonian Institution has been sponsoring is that the flagrant nostalgia and veiled chauvinism of such productions are not permitted to blur the vitality of authentic style. True to type, the two Caribbean groups that performed in Baird Hall on Saturday didn't refrain from tugging at tribal feelings while they carefully minded manners that proved to be distinct.

Molly Ahye's Co. from Trinidad and Tobago enjoyed itself unashamedly. Ahye, a mature woman of impressive proportions, led her young troupe onto the stage with feathered step. Then, like a sorceress, she moved aside to control the proceedings with mere glances. Among those proceedings were a few show-biz combinations that, like the flamboyant calypso and sensual incantations, presumably have become folkways.

La Familia Cepeda, from Puerto Rico, has a brusque attitude toward its skits, music and dancing. The family's patriarch disdained looking directly at the center of action as he stood to the side singing. Ten lads dealt in a perfunctory way with the step, stoop, slice and pick motions of a harvest dance. Aloof pride more than pleasure was expressed in vibrating-motion solos of considerable virtuosity.