Significance and p-values

How do I interpret my results?

There's a measurement called the "p-value" which a statistical test returns. The p-value indicates how likely it is that you would have seen the difference between your experimental and control conditions if the null hypothesis were actually true.

The smaller the p-value, the more likely it is that the difference between your experimental condition and your control condition is the result of a "real" difference, and not random chance.

In the behavioral sciences, there's a tradition that the value at which one can publish is p <= .05 -- so less than a 5% chance that you would have gotten this data if the difference were not really there.

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