Q: Why is that sometimes a research can be replicated but not its finding?

Hi Laura – Welcome to the forum! We understand you may have posed a similar query over the weekend. So, we have consolidated both into one query. If that other query wasn’t by you, well, hopefully, that researcher will see (and gain) from this response. :-)

Coming to your query, these discrepancies, in fact, often provide vital clues and result in more fruitful research because they set scientists thinking: ‘What is it that I did differently that led to unexpected results?’ The reasons can be many, and much depends on the materials. Biological materials, for example, can vary a great deal: blood of different blood groups; fruits of different size, shape, and color; even the grade of chemicals (analytical-grade substances are purer than industrial-grade substances). Ambient conditions also vary: temperature, humidity, intensity of sunlight, and so on. Then, there is the element of chance, which is why you have P values and confidence intervals and replications.

The ideal is to keep everything the same except the factor under investigation, but that is seldom possible. It is for such reasons that in writing the Methods section of your research paper that you are expected, for example, to supply the make and model of any scientific instrument you used, the sampling method and the number of samples, and so on.

In short, the results of following the same procedure may be different because of inherent variability of materials and chance. The great the experimenter’s control over these factors, the more reproducible the results.

For more information on the matter of reproducibility/irreproducibility, you may refer to the following resource: Irreproducibility: The soft underbelly of science

And for help with writing the Results section, you may look up this resource: The secret to writing the Results and Discussion sections of a manuscript

All the best with your research!