- the document is fundamentally unsuitable for translation
- the document should actually have been produced in a word processor or a DTP program
- the document is utterly pointless garbage
It appears that in the wider world of business, people with not enough to do are commonly set to produce "presentations" for "meetings"; I admit that this falls largely outside my first-hand experience - I can't help it if I'm lucky. As far as I can tell, the form appears to be that the slideshow is used as supporting material for a spoken presentation, with the futile aim of reinforcing Key Points. (Research has in fact demonstrated [citation needed] that this doesn't actually work - they just disorient or distract the listener/viewer. But they persist.) The upshot of this is that these slideshows consist by and large of slightly repetitive laundry lists of unexplained concepts, often linked together with arrows in a way which reflects either some hidden structure, or just the speakers' normal hand gestures. Since the explanations are not Key Points, they are relegated to the spoken element of the presentation. Now, should it be decided that this exercise is to be conducted in a different language, the .ppt is duly shipped off by some member of secretarial staff to the company's translation agency of choice, whose harassed project manager duly places it with a translator, who is now, as is commonplace, at three or four steps distant from the originator of the file.
Now fairly early in a translator's career, you discover that context is key to, well, lots of stuff. Which means that laundry lists - more or less context-free lists of terms - are a right pain in the arse to translate at the best of times. Lists of industrial components or stock for sale look easy but always contain something nightmarishly obscure that will take a week to research at a few cents per word, while restaurant menus invariably contain 57 varieties of unresolved ambiguity, often expressed in purest Hello Kitty kitsch (which is why I will only consider translating them on an hourly rate plus the expenses incurred for a research visit to the kitchens, an offer which has yet to be taken up). But at least there you have something concrete to go on, however full of fantaisie. When all you have is, in effect, inchoate note-form reminders to help someone speak who, to some extent at least, knows what they intend to talk about, but hasn't told you, you are in trouble. There is nothing for it but to put on your best mind-reader's hat and interpolate the talk that is to be given between clicks on the "next" button. Which is to say, guesswork and hackwork (as in hack writer rather than definitions 1 to 7 of hacker in the Jargon File) and keep your fingers crossed.
Of course, one side effect of this presentation culture is that the perpetrators often become sufficiently enamoured of the tool that they start using it for inappropriate purposes (Excel jockeys are also serial offenders in this respect). We have more than once been confronted with .ppts which are clearly intended to be printed out as booklets; maybe they wanted landscape format and hadn't worked out how to change it in Word. At least in these cases you ought not to require telepathy, or at least, no more than is usual in the profession, but you will run up against the other fundamental issue: PPt is a lousy text editing environment, because it is designed as a visual tool, not a textual one. The more lovingly the authors have laid out their slides, the bigger a hash it will make when your text is not the same length as the source. It is more or less impossible to change the language settings, so you won't be able to spell check anything. If you use a translation memory program, it is likely to run up against the non-linear nature of text in randomly placed little boxes (Déjà Vu X has been known to go as far as importing the slides in an apparently random order, for added spice, and I name it as a culprit only out of ignorance of the many alternatives); better still when (like many PPt users) your author has not yet found out how to make text boxes wrap and has therefore split running text into different text boxes in order to lay it out right. At which point you can basically give up hope of using TM in any form.
So just say no. And after you have, as usual, failed to say no well enough, let them clean up their own bloody text that, once translated, bleeds over their cool clipart or over the edge of the slide itself. And charge by the hour.
*I imagine that this also applies to material created using OpenOffice Impress or any of the other fine presentation software available on the market, but I've never actually seen any of them in the wild