significanciasignificância

Significância is a term used in statistical hypothesis testing to describe the probability of obtaining observed results, or more extreme results, if the null hypothesis were true. It is commonly denoted by the Greek letter alpha (α) and is a predetermined threshold, typically set at 0.05 or 0.01.

When the calculated p-value of a test statistic is less than the chosen level of significância, the null hypothesis is rejected. This suggests that the observed data are unlikely to have occurred by random chance alone, implying a statistically significant effect or relationship. Conversely, if the p-value is greater than the significância level, the null hypothesis is not rejected, meaning the results are not considered statistically significant at that chosen alpha level.

The choice of the significância level is crucial. A lower significância level (e.g., 0.01) requires stronger evidence to reject the null hypothesis, thus reducing the risk of a Type I error (falsely rejecting a true null hypothesis). A higher significância level (e.g., 0.10) makes it easier to reject the null hypothesis but increases the risk of a Type I error.

It is important to note that statistical significância does not necessarily imply practical or real-world importance. A statistically significant result may be very small in magnitude and have little bearing on the phenomenon being studied. Therefore, interpreting results requires considering both statistical significância and the effect size.