Does the a priori belong to science and technology?

In this paper, I intend to support a currently controversial approach to the a priori -- the one that respects its fundamental role in science, and I furthermore suggest the relevance of the a priori may be expanded to technology. I shall address the following three issues: a priori in scientific and technological methodology, a priori and the essence of science and technology, and a priori in the assessment of science and technology.