Why do scientific experiments (mainly in neuroscience and psychology) need to be done on more than 1 person? I was under the impression that the most important part of determining the study’s accuracy was to ensure that the outcome had a less than 5% chance of occurring without the theorised variable.
Couldn’t a situation emerge where the outcome was almost certainly attributed to the variable in question even with one person. For example, something extremely random, like (stupid example) a blood clot forming in someone’s left pinky finger after being reminded of childhood trauma (and it was predicted beforehand).
In: 0
I want to diverge from some of the other answers slightly and say that research on small samples, or even a sample of 1, can be the most appropriate choice in some contexts.
The most obvious example is when researchers or practitioners come across unusual one-off outcomes. Sometimes, a doctor might see something really strange in a particular patient that they have never seen or heard of before. Or an engineer might be investigating a structure that has failed in an extremely unusual way. They will often write this up and publish it as a “case study”. This might be helpful to someone who encounters exactly the same situation in future, or someone might be able to combine it with other information to help understand some underlying mechanism.
Also, there is an advantage of small samples in that you can study the individuals in the sample in more detail. Suppose, for example, that you want to understand people’s political views. You might design a survey and send it out to a representative sample of 1000 people. You can be confident that your results will be reasonably representative of the population, but unfortunately it’s hard to ask anything but extremely superficial questions (“Which party do you support?”, “Do you support the death penatly?”, etc.) to such large numbers of people. Alternatively, you could conduct detailed interviews with 10 people. These results will not be representative of the population, and some of what you pick up might just be unique quirks of these specific people, but on the other hand you can ask lots of searching questions and get an in-depth understanding of how each individual thinks about politics.
An extreme example of that is when people are essentially studying themselves, which happens quite a lot in parts of the humanities. Philosophers will often spend a lot of time focusing on their own thought processes, because you can never understand other people’s thoughts as deeply as your own. Anthropologists will spend a lot of time thinking about their own interactions with the population they are studying. And so on.
Latest Answers