lab3-5

12/12/23, 12:14 AM Getting started with statistics in R, Part 3 https://mattar.shinyapps.io/lab3/#section-two-sample-t-test 3/5 Just like with a one-sample -test, the output tells us a number of things: 1. What type of test we ran 2. What data we ran it on 3. Our -value, our degrees of freedom, and our -value 4. What our alternative hypothesis is 5. The lower and upper limits of a 95% Confidence Interval 6. The sample means (now we have two estimates because we have two groups) Welch’s two-sample -test However, if we didn’t meet the assumption of homogeneity, we would have to run a Welch’s -test instead. The way to do this in R is to simply specify var.equal=FALSE . R runs a Welch’s -test by default (if don’t set var.equal at all). R Code  Start Over ▶ Run Code Two Sample t-test data: inferences by condition t = 6.9533, df = 356, p-value = 1.714e-11 alternative hypothesis: true difference in m eans between group generic and group specifi c is not equal to 0 95 percent confidence interval: 0.7807843 1.3966351 sample estimates: mean in group generic mean in group specifi c 2.75000 1.6612 9 t.test(inferences ~ condition, data = data, t t p t t t R Code  Start Over ▶ Run Code t.test(inferences ~ condition, data = data, 1 2 3 1 2 3 Getting started with statistics in R, Part 3 Tutorial by Kelsey Moty Before you get started (https://mattar.shinyapps.io/lab3/#sectio before-you-get-started) Running basic inferential tests in R (https://mattar.shinyapps.io/lab3/#sectio running-basic-inferential-tests-in-r) -test (https://mattar.shinyapps.io/lab3/#sectio z-test) z One-sample -test (https://mattar.shinyapps.io/lab3/#sectio one-sample-t-test) t Two-sample -test (https://mattar.shinyapps.io/lab3/#sectio two-sample-t-test) t Paired-samples -test t Plotting our data Start Over