American Institute of Certified Planners (AICP) Practice Exam

What does it mean when statistical results are categorized as significant?

1. The results are random

2. The results occurred by chance

3. The results are unlikely to occur by chance

4. The results are within normal range

The correct answer is: The results are unlikely to occur by chance

When statistical results are categorized as significant, it means that the results are unlikely to occur by chance. In the context of hypothesis testing, significance typically indicates that there is enough evidence to reject the null hypothesis, which states that there is no effect or difference. When a result is deemed significant, it suggests that the observed effect or difference is meaningful and not due to random variation in the data. The significance level, often set at 0.05 or 0.01, provides a threshold for determining whether the findings are statistically significant. If p-values are below this threshold, it implies a high level of confidence that the results reflect true effects in the population being studied, rather than random fluctuations. The other options relate to misinterpretations of significance. For instance, categorizing results as random or occurring by chance would negate the significance, while results within normal range do not convey the same implications about the likelihood of occurrence. Therefore, recognizing that significant results indicate an improbability of occurring by chance is critical in understanding statistical analysis.