The main negative criticism against distance learning is that laboratory work is an essential part of all branches of technology and natural sciences. One can infer that this is so from two observations: (a) Colleges have residence requirements mainly because the faculty believes that this creates an opportunity for practical work; (b) Many scientists, like Carl Sagan and Karl Popper, think that controlled observations are important components of the learning process (Popper, 2002, p. 191). Even in human sciences, hands-on work prevents blueprints for unrealistic social engineering projects. In arts, supervised practice and rehearsal is desirable, to say the least. In Earth sciences, Astronomy, and Astrophysics the student has to examine paleobiological records, reconstruct the history of sediment records, collect samples or investigate the availability of samples from individual researchers and repositories, perform observations, and deploy data acquisition systems. Most distance learning systems ignore observations, practice, sample collecting, and laboratory work. Therefore they are vulnerable and open to criticism in regards to the experience and practical knowledge, given by those institutions that offer degrees based on distance education, and so are not recognized in many countries.
The World Wide Web was searched for accredited distance education degrees in the United States, Canada, and Australia; if one is to believe in the completeness of sites like Guide to Online Schools (2000), most institutions limit their activities to business, law, religious studies, and social services. There are very few Engineering degrees, most of them recognized by the Commission of the Distance Education and Training Council (DETC), which the U.S. Department of Education (2007) recognizes as an accrediting agency; however, the catalogs of institutions that offer this kind of education list only Associate degree programs, which means that their alumni will work under the supervision of an Engineer, or Master in Engineering, which implies that the student already has a degree in Engineering.
From the above discussion, it seems that critics of distance learning, providers of online education, and accrediting commissions agree that engineering, natural sciences, and other subjects where laboratory work is mandatory require residence for graduation. The rationale is that distance learning cannot provide the practical expertise needed for some endeavors.
Most scientists adopt either classical empiricism or Popper critical rationalism guidelines for their work. Classical empiricism is based on experiments and observations followed by inductive reasoning. In the words of English philosopher and statesman Francis Bacon (2007, chapter CXVII), one can say that:
“...via nostra ea est; ut non opera ex operibus..., sed ex experimentis causas et axiomata, atque ex causis et axiomatibus rursus nova opera et experimenta extrahamus.” Trad. “...our method is the following: We do not extract theories from previous theories, but from experiments we extract causes and axioms, and from these causes and axioms we extract new theories and new experiments”.
Popper disagrees with Bacon in holding that scientific theory is hypothetical, and is generated by the creative imagination in order to solve problems; he also believes that no number of positive outcomes of experimental testing can confirm a scientific theory, but a single counterexample is decisive: it shows the theory to be false. He also takes falsifiability as the single criterion of demarcation between what is and what is not science: a theory should be considered scientific if it is falsifiable. No matter which approach one takes, laboratory work and observations can be considered the corner stone of science; Popper says: the experiment is “a rational reconstruction of the steps that have led the scientists to a discovery – to the finding of some new truth.” (2002, p. 8). From what has been said, one can conclude that laboratory work and practice in teaching of science is beyond challenge. What is challenged by the authors of this article is that distance education cannot provide the indispensable feedback that students need from Nature.