From the script of The Mother of all Demos (its 50th anniversary noted elsewhere in HN)[1]:
"...the general approach for us, empirical but pursuing this monstrous goal, monstrously difficult to like building and trying empirically, and we’re approaching it evolutionary-wise because we feel that it’s a whole system problem, you need to get a person in that environment, working and looking at the many aspects of his working system that are involved in his effectiveness. That’s many more things than just these computerated tools. And in a large system like that, we need to do it evolutionary-wise because we can’t be analytic enough about it at any one point, to decide what best our next thing should be. We can only decide from here as well as we can analyze it, where we can invest our next resources to get the most return that will increase of the effectiveness of the system we have and this item down here is the term boot-strapping applied in a slightly loose sense. We’re applying that to our approach".
"...the general approach for us, empirical but pursuing this monstrous goal, monstrously difficult to like building and trying empirically, and we’re approaching it evolutionary-wise because we feel that it’s a whole system problem, you need to get a person in that environment, working and looking at the many aspects of his working system that are involved in his effectiveness. That’s many more things than just these computerated tools. And in a large system like that, we need to do it evolutionary-wise because we can’t be analytic enough about it at any one point, to decide what best our next thing should be. We can only decide from here as well as we can analyze it, where we can invest our next resources to get the most return that will increase of the effectiveness of the system we have and this item down here is the term boot-strapping applied in a slightly loose sense. We’re applying that to our approach".
[1]: http://dougengelbart.org/pubs/video/fjcc68/Englebart's-1968-...