HOW TO SET UP , CONDUCT AND REPORT A SCIENTIFIC STUDY
Original Articles
Figure 4a . Graphical display of experimental design ( Courtesy of Dr . Uwe Blunck , Berlin ).
did etc .) is put in the past tense ( e . g . Van Meerbeeck et al reported that self etching adhesives yielded a thinner hybrid layer than etch & rinse adhesives ) and only things that are generally accepted should be written in the present tense ( eg . saliva is a buffer or chloroform is a solvent ). Every statement in an introduction must be backed with a literature quote . At this stage it is recommended to put the literature quotes in parentheses with just the author names and the year . If the same author has published more than one quoted paper in the same year , then the specific article may be identified with letters : a , b , c , etc .). This leads to the question what should be quoted and listed ?
• Earlier work in the area
• Methodology used
• Other publications of importance
• ONLY publications actually used in text ! Common errors are that the literature search has failed to find relevant papers to the topic . Often secondary literature is quoted instead of the original source ( e . g . Roulet described the use
of Silane in composite formulations in his thesis , referring to Pluddemann et al as the inventers of Silane . An author uses Roulet as a reference for Silane ). Another error is quoting a paper for a certain fact that was not described in the quoted paper and finally the quote of opinion instead of experimentally based facts is not correct as well . Today more and more publishers use software to detect plagiarism . This reveals yet another common error : that of the simple use of copy paste to insert text fragments from other articles ( even your own !) into your own paper without putting the text in “” and quoting the source . Finally not acknowledging work of your competitors and quoting only your own papers is not an error per se , but a fact that sheds a bad light on your person . Once the objective is clear , the author must provide a way to solve the problem . This is described in “ Materials & Methods ”. What to do must be described to the smallest detail BEFORE the experimentation begins and once it has been defined it may NOT be changed , because the situation most likely occurs that the results cannot be correlated to the investigated parameters anymore ; the change has introduced another variable . This is big trouble . If a standard method is used , it is sufficient to describe it and to refer to its source . Furthermore it is highly advisable to practice it before it is used for the experiment . If this is ignored , bias is introduced , because the inevitable learning curve is included into the results produced . Very often some new equipment or procedures are used to address a research question and the usefulness is not known . Therefore in these situations usually a pilot study should be performed . It should be dealt with identically to the real experiment , but with a substantially smaller sample size ( feasibility study ). The outcome of the pilot study may lead to modifications of the “ Materials & Methods ” of the main study . The report of a pilot study may either be inserted after the “ Introduction ” reporting its “ Materials &
Figure 4b . Graphical display of balanced experimental design .
94 Stoma Edu J . 2017 ; 4 ( 2 ): 90-101 http :// www . stomaeduj . com