If a confidence interval crosses 0, what does this indicate?

When a confidence interval crosses zero, it indicates that there is a possibility of no effect or no difference in the population being studied. This means that the statistical test may indicate that the result is not significantly different from zero, implying that the effect observed in the sample may be due to chance rather than a true effect in the larger population.

In terms of statistical significance, if the confidence interval includes zero, it suggests that you cannot confidently assert that there is a significant effect, leading to the interpretation that the result could indeed be statistically insignificant. Therefore, while the analysis may have produced specific point estimates, the conclusion from the confidence interval suggests that there isn't strong evidence against the null hypothesis, which usually posits that there is no effect.