I got my Bh.P. many long years ago; I’ve been repeatedly, dogmatically, arbitrarily, and serially guilty of Buttheaded Prescriptivism. Only relatively recently have I worked at sanding down the sharp edges and rounding off the pointy corners with some goodly hyphens dashes of descriptivism. Just yesterday I was scrubbing my bathtub when it occurred to me how capricious, inconsistent, and silly is my objection to the use of the nouned verb ‘In·stall’, with the accent on the first syllable, rather than ‘In·stal·la·tion’. My own Stern Style Guide right here on this very site is full of equal and opposite objections to morbidly obese redundancies like ‘Trans·por·ta·tion’ instead of ‘Trans·port’ and ‘Im·por·ta·tion’ instead of ‘Im·port’. By the same dint, if I’m to be consistent I have to deprecate ‘Installation’ and favour ‘Install’. There’s nothing structurally the matter with it; we noun verbs—and vice-versa!—all the time in English: ‘Pro·ject’ (noun), ‘Pro·ject’ (verb); ‘De·tail’ (noun), ‘De·tail’ (verb); ‘Ad·dress’ (noun), ‘Ad·dress’ (verb); ‘Re·ject’ (noun), ‘Re·ject’ (verb); ‘Re·tard’ (not-very-nice noun), ‘Re·tard’ (verb). Sometimes we don’t—witness ‘Ex·haust’, noun and verb alike—but that’s probably because a needlessly-lettery nouned verb like ‘Ex·haus·ta·tion’ would be silly and needless. Just about as silly and needless as ‘Installation’, as it seems.