Multiple accounts of plagiarism (?) during literature study: are my standards too high or should I take action? I'm currently doing my literature review in preparation for my graduation (masters degree) thesis work at a Dutch university. The past semester I worked as a student assistent on a first-year project, that had quite a heavy focus on learning to properly cite and refer to source material. Together with the project supervisor, we'd run all student reports through plagiarism checking software. If we found anything wrong or suspicious, we confronted the students and explained them that their current practice was not the way to go. For example, when a group failed to put quotation marks if they'd literally copied something, we gave them a warning, even though they did include a reference. We upheld high standards.

Fast forward to my current work doing my literature research, in which I'm trying to figure out and document the exact workings of a number of software programs - in order to make a detailed comparison supporting selection of a subset of these programs for inclusion in my thesis research. Some of these codes are well-known and open source, others are quite obscure. Especially for the less-known ones, I'm coming close to the point of having read (or at least: knowing about the existence of) all sources there are on that program, and where I'm able to basically guess what paper a numerical reference points to - simply based on content. 

Today, I've come across a PhD-thesis in which a full paragraph was directly copied (not formatted as a blockquote or similar) from a journal publication, not written by the PhD-candidate or supervisors. That paper is mentioned (on a previous page), but quotation marks are absent from the copied paragraph. This is not the first time I've seen something like this (also noted a few conference papers doing this) and it leaves me quite confused. 


If this is acceptable, aren't the standards I used to teach to my student groups ridiculously high? I'm also adhering to these standards, which not always comes easy. For example, I'm sometimes going through hell and back again to find the original source of something and/or including secondary references, other times including lengthy footnotes on how I think contradictory information might have been mangled up in a chain of citations and pointing out potential errors in peer-reviewed publications. Similarly, I feel I'm walking the line when putting "The information in this section is obtained from reference X, unless indicated otherwise", rather than including a reference after every individual sentence in that section.
If this is not acceptable (and the 'high' standards are indeed the standards), what should I do about the plagiarised texts I have come across - and might come across in the remainder of my review? Accept it, shrug it off and do better myself, or take this up with somebody from university? 


I realise there might not be an absolute, factual answer to this question - but I'm hoping it is 'allowed'. Other knowledgeable sources that I know are employed at this university and I'd rather first get some external advice/ideas - before becoming the whistle-blower or wrongly accuse people.

Edited the first and second paragraphs (italicized parts) for clarity.
It's also worth noting that conventions on citing and quoting are not universal, and can vary between academic communities.  For example, in mathematics, it is quite common to copy definitions or statements of theorems verbatim, or nearly verbatim, from other papers.  The precise wording and notation can be critical, so wholesale paraphrasing is risky.  However, the convention in this field is that quotation marks are not used in such cases, though a citation should usually appear.  Likewise, if a definition or statement is "common knowledge", it might be that every paper discussing it uses almost identical wording (maybe without citations), even though they have not consciously copied from each other.

(I don't really know how this practice arose, but one point is that it often happens that you want to state a theorem almost verbatim, but modify the notation to match what you're using in the present paper.  Now it's not an exact quote anymore, so you can't strictly use quote marks, and noting your amendments with brackets could be very confusing when mathematical notation is involved.)

This can add up to several paragraphs or pages of "copied" text over the course of a paper.  A newcomer to the field might see this and be horrified by the blatant "plagiarism", but within the field it's regarded as perfectly proper.

Additionally, it's completely normal in mathematics to write things like "The material in this section comes mainly from [3]" without adding [3] to every other line.  It's more about common sense than following rules.

So, the moral is to make sure you're calibrating your standards properly to the specific discipline in which you're working.