true or false, we can be reasonably condent when the level of condence is 95% or more. The level of condence indicates the percent of time that a series of condence intervals includes the unknown population characteristic such as the population mean. An increase in condence interval causes a wider confidence interval that is less (15) unless it is offset by an increase in (16) . Although many different levels of condence have been used, (17) and (18) are the most prevalent. Condence intervals are more narrow or precise when standard error is smaller. Since standard error is reduced when sample size is increased, the larger the sample size, the more precise the condence interval. In the behavioral science, hypothesis tests have been preferred to condence intervals. However, (19) are more informative because they indicate the size of the (20) . Ahypothesis test is most appropriate when the major concern is whether or not an (21) is present. Otherwise, a condence interval could be used and should be considered when the null hypothesis is reiected