both the experimental and control groups showed no significant changes in their beliefs after reading the articles, as the mean differences in pretest and posttest scores were zero for both groups. The null hypothesis, which is the default assumption that there is no significant effect or relationship, is supported in this case. This means that the articles did not significantly influence the participants' beliefs. Cohen's d is a measure of effect size, which assesses the magnitude of the difference between two groups. A negative effect size indicates that the control group had a higher score than the experimental group. However, the value of -2.56 is quite large, suggesting a substantial difference between the sample mean difference and the population mean difference. This could mean that while the articles did not significantly change beliefs within the sample, there might be a significant difference when applied to the population. However, without context or additional information, it's hard to interpret this effect size accurately. summarize into APA format