I've had some discussions in the past with TA's who would tell my undergrads "Lab reports are written in the passive voice".
Aside from whether or not this is correct (let's come back to that in a bit), where does this come from? Some guidelines I've found that insist on the passive voice (e.g., http://guides.lib.purdue.edu/content.php?pid=232776&sid=1925925) claim that this is done to de-emphasize the role of the investigator, and thus provides a tone of objectivity.
Such arguments never seem to have attribution. Is this a commonly accepted reason, or simply a rationalization?
In effort to prevent this from becoming an opinion-based argument, can anyone point me to a major scientific journal's style sheet or instructions to authors that specifies passive voice for scientific communication? I've published in a number of them, and never came across such an instruction.
As to whether passive voice is correct in this context, I'm thinking of telling my students that there has been a historical tendency to use passive voice for scientific communication, but there seem to be recent trends promoting active voice. I'll point them to examples of both (the previous link and http://writingcenter.unc.edu/handouts/scientific-reports/ for the counter-example), and tell them that I'll accept either style (It will alleviate boredom during grading, if nothing else). Does that sound like an acceptable approach?