In this work I review the three concepts of technological paradigm, sailing-ship effect and presumptive anomaly. The first concept is almost universally acknowledged, while the second and the third have a niche audience, and this is why I bring them to the fore. Taken together, the concepts explain: first, what structural knowledge and concrete components of a technology are; second, why an ‘old’ incumbent technology may experience a new lease of life when threatened by a new technology through a specific kind of response, i.e. the sailing-ship effect; and third, contrary with respect to the previous case, why an alternative to a perfectly working and improvable technology may be sought.