But it was the summary that made her lean back in her chair.
For six months, she had poured her grant money into this experiment. The hypothesis was simple: Drug X would raise the cellular metabolic rate in vitro. But after all the pipetting, the overnight incubations, the careful calibration of the luminometer, she was left with these five numbers on the left and five on the right.
Her advisor, the gruff Dr. Mullaney, had given her one piece of advice before retiring to his fishing cabin: "Elena, don't trust your eyes. Trust the p-value. And for God's sake, don't do the math by hand. Use the green one." graphpad quickcalcs t test calculator
She closed the tab. She opened her manuscript draft. She typed a new sentence: "Treatment with Drug X resulted in a statistically significant increase in metabolic rate compared to placebo (unpaired t test, p = 0.0003, n=5 per group)."
Elena felt a wave of relief wash over her. The drug worked. The p-value was not 0.05. It was not 0.01. It was three zeros. It was the kind of p-value that reviewers squint at, check twice, and then grudgingly accept. But it was the summary that made her lean back in her chair
She scrolled up. The calculator had been generous. It gave her everything: the mean of Group A (12.40), the mean of Group B (10.10). The difference (2.30). The 95% confidence interval of that difference (1.59 to 3.01). The F test for equal variance (passed). The t ratio (7.23). The degrees of freedom (8).
She looked back at the GraphPad QuickCalcs page. It hadn't changed. It was still just a white box, some radio buttons, and a few lines of text. It didn't congratulate her. It didn't ask her to subscribe. It didn't even have a logo. But after all the pipetting, the overnight incubations,
The two-tailed P value equals 0.0003