I did a biology undergraduate degree and often did reports where would statistically analyse our results. P value of less than 0.05 shows that the results are statistically significant. How do these tests actually know the data is significant? For example we might look at correlation and get a significant positive correlation between two variables. Given that variables can be literally anything in question, how does doing a few statistical calculations determine it is significant? I always thought there must be more nuance as the actual variables can be so many different things. It might show me a significant relationship for two sociological variables and also for two mathematical, when those variables are so different?
In: Mathematics
When we find a relation with a small p-value we are essentially saying there is a small chance that the relation is due to random chance. This then allows us to accept a hypothesis as a certain level of confidence.
When using p-values and other statistical methods you are looking to either accept or reject a hypothesis that you have created. Frequently, we use the null and alternative hypothesizes for simplicity. When creating a testable hypothesis it needs to pass the sniff test. Historically, the butter production in various countries has had a an significant relation to the returns of the S&P 500. This doesn’t mean that the relation is neccesarily true though.
With the ridiculous number of possible relations in our data rich world there will be significant relations between variables that make no sense. The probability of getting 10 heads in a row is incredible small but in a set of 100,000 flips its actually fairly likely. The way to get around this is either using common sense in data and relation selection or to find significant relations in comparable data.
The correlation between worldwide non-commercial space launches and Sociology doctorates per year is high but does it really mean anything? Maybe if space launches correlate with science funding and total doctorates also increase with global science funding? Maybe the US has the majority of space launches and so it makes more sense. A high probability does not imply truth.
https://blog.psyquation.com/es/correlation-with-a-twist/
Latest Answers