http://blogs.scientificamerican.com/information-culture/2013/10/29/you-cant-read-just-one-reproducibility-and-multiple-sources/ 
There are lots of ways to mess with the heads of undergraduate students. Giving them a research assignment and failing to specify a minimum number of references needed is just one example.
“Include as many sources as you need to make your point and illustrate your thesis.”
For students, finding one scholarly article on their topic often 
seems to be enough.  Researchers did an experiment, got some results, 
and answered the research question the student started with. All done, 
all set, time for dinner.
But science doesn’t work that way. One experiment may suggest 
something interesting, but it doesn’t prove anything.  In fact, it is 
quite easy to point to many examples of intriguing scientific studies 
that were either proved false or that couldn’t be reproduced later on.  
Scientific ideas that are true should be reproducible: other researchers
 should be able to repeat the experiments and get similar results or use
 other methods to arrive at the same conclusions.  You can’t say that 
you discovered something new if someone else can’t reproduce your 
result.
This fundamental scientific idea, reproducibility, may be in crisis. 
 A recent article by Vasilevsky et al. in the journal PeerJ suggested 
that many scientific journal articles don’t provide the information that
 other scientists would need in order to replicate their results.  Key 
information about chemicals, reactants or model organisms is often 
missing, despite journal requirements to include such information 
(Vasilevsky et al., 2013).  And a recent item in 
The Economist 
suggests that this might not matter that much.  The emphasis placed on 
new research (by funding agencies and tenure and promotion committees) 
means that few scientists even attempt to replicate the work of others 
(“Unreliable research: Trouble at the lab,” 2013).
All of this means trouble from the very beginning of a research 
project, before an experiment is even designed, when scientists start to
 do background research on their topics. In the same way that 
experimental scientists can’t rely on the results of just one experiment
 to prove something, relying on just one information source for 
knowledge is a sure way to end up with unreliable information. 
Journalists look for corroborating sources, wikipedia flags articles 
that need a wider variety of citations, and scholars need to find 
multiple scholarly articles to support their ideas.
Some innovative people, companies and publishers are trying to sort 
this mess out.  A collaboration between PLOS ONE, Mendeley, Figshare and
 the Science Exchange will be attempting to replicate the results of 
selected projects as a part of the 
Reproducibility Initiative.  The 
Reproducibility Project is a crowdsourced effort to evaluate the reproducibility of experimental results in psychology. And the 
Reproducible Science
 project aims to make the results of computational experiments 
reproducible by ensuring the sharing of code and data and by making that
 information available to reviewers who can test the results described 
in a manuscript they are reviewing.
Unfortunately, these innovative programs are just a drop in the 
bucket of modern science.  Funding agencies, publishers and tenure and 
promotion committees still value original work more highly than 
verification work. Scientists who concentrated on replicating the work 
of others would risk their careers.
As a result it is important for students and scholars to be aware of 
the challenges facing the reproducibility of science. We teach students 
in introductory science classes that reproducibility is one of the 
hallmarks of science.  As they learn more about their disciplines, they 
need to be aware of the practical challenges involved in reproducing the
 work of others, and the importance of finding multiple sources about a 
topic needs to be emphasized.
As a librarian, part of my job is to help students find additional 
sources related to their research topics, even if there isn’t a 
published reproduction of an original source.  This isn’t about which 
database to use or whether to put quotes around a phrase.  It is about 
getting them to think critically about their topics.  For example, while
 there might not be a second study that repeated the experiment of the 
first, students can look for:
- Studies that examined the same topic in a different way
- Studies that used the same methodology on a different species, geographic area, etc.
- Background studies on individual aspects of their research question, including the statistical analyses used
- Studies that cite the original study (even if no one has tried to 
reproduce the results, other scholars might express doubts about their 
conclusions when they cite the original).
The issues surrounding reproducibility in science won’t be solved 
overnight, and it will take a concerted effort from scientists at all 
levels of the modern scientific enterprise to steer this very big ship. 
 In the meantime, students and scholars can make special efforts to 
ensure that they are using the highest quality information available as 
the basis of their original studies.
Works Cited:
“
Unreliable research: Trouble at the lab.” (2013, October 19). 
The Economist, 
409(8858), 26-30.
Vasilevsky, N. a, Brush, M. H., Paddock, H., Ponting, L., Tripathy, 
S. J., Larocca, G. M., & Haendel, M. A. (2013). On the 
reproducibility of science: unique identification of research resources 
in the biomedical literature. 
PeerJ, 
1, e148. doi:
10.7717/peerj.148.