{"id":9720,"date":"2023-04-27T01:59:59","date_gmt":"2023-04-27T01:59:59","guid":{"rendered":"https:\/\/support.divominer.com\/en\/docs\/divominer-user-manual\/advanced-statistics\/t-test\/"},"modified":"2023-11-08T03:27:12","modified_gmt":"2023-11-08T03:27:12","slug":"t-test","status":"publish","type":"docs","link":"https:\/\/support.divominer.com\/en\/docs\/divominer-user-manual\/advanced-statistics\/t-test\/","title":{"rendered":"t-Test"},"content":{"rendered":"\n<p><strong>1. t-Test<\/strong><\/p>\n\n\n\n<p>The t test, also known as the student\u2019s t-test, is a statistical hypothesis test used to determine whether there is a significant difference between the means of two independent samples. It is often used in research and data analysis to test hypotheses about the mean of a small sample drawn from a normally distributed population when the population standard deviation is unknown. The t-test uses the t-distribution theory to infer the probability of a difference, and compares whether the difference between two means is significant. Here are the differences between some of the most common tests of hypothesis:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"566\" height=\"256\" src=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/21.png\" alt=\"\" class=\"wp-image-9723\" srcset=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/21.png 566w, https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/21-300x136.png 300w, https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/21-50x23.png 50w, https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/21-320x145.png 320w\" sizes=\"(max-width: 566px) 100vw, 566px\" \/><\/figure>\n\n\n\n<p><strong>2. One-sample, two-sample, and paired t test<\/strong><\/p>\n\n\n\n<p>There are different types of t test based on whether the groups being compared come from a single population or two different populations: one-sample, two-sample (a.k.a the independent t-test), the paired t-test. If there is one group being compared against a standard value, perform a one-sample t test; the independent samples t-test compares the means of two separate groups, and the paired t-test compares the means of two related groups.<\/p>\n\n\n\n<p>The one-sample t-test is used to analyze whether the quantitative data (in a normal distribution) is significantly different from a given value, such as comparing the acidity of a liquid to a neutral pH of 7. The formula for the one-sample t-test is:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"114\" height=\"78\" src=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/8.png\" alt=\"\" class=\"wp-image-9724\" srcset=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/8.png 114w, https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/8-50x34.png 50w\" sizes=\"(max-width: 114px) 100vw, 114px\" \/><\/figure>\n\n\n\n<p>Where <img loading=\"lazy\" width=\"73\" height=\"31\" src=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/9.png\" class=\"wp-image-9725\" style=\"width: 73px;\" alt=\"\" srcset=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/9.png 73w, https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/9-50x21.png 50w\" sizes=\"(max-width: 73px) 100vw, 73px\" \/>&nbsp;<img loading=\"lazy\" width=\"87\" height=\"43\" src=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/10.png\" class=\"wp-image-9726\" style=\"width: 87px;\" alt=\"\" srcset=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/10.png 87w, https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/10-50x25.png 50w\" sizes=\"(max-width: 87px) 100vw, 87px\" \/>&nbsp;is the mean of the sample, \u03bc&nbsp;is the overall mean, <img loading=\"lazy\" width=\"25\" height=\"28\" class=\"wp-image-9727\" style=\"width: 25px;\" src=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/22.png\" alt=\"\">is the standard deviation of the sample, and n is the sample size. The statistic t obeys the t-distribution with n degrees of freedom under the condition that the null hypothesis: \u03bc=\u03bc0 is true.<\/p>\n\n\n\n<p>The two-sample (independent sample) t-test is used to test the differences in two different populations, such as to test whether there is a significant difference in two different species, or people from two separate cities. The formula for the independent samples t-test is:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"353\" height=\"102\" src=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/13.png\" alt=\"\" class=\"wp-image-9728\" srcset=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/13.png 353w, https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/13-300x87.png 300w, https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/13-50x14.png 50w, https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/13-320x92.png 320w\" sizes=\"(max-width: 353px) 100vw, 353px\" \/><\/figure>\n\n\n\n<p>Among them, <img loading=\"lazy\" width=\"21\" height=\"28\" class=\"wp-image-9736\" style=\"width: 21px;\" src=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/14.png\" alt=\"\">and <img loading=\"lazy\" width=\"17\" height=\"19\" src=\"\"><img loading=\"lazy\" width=\"27\" height=\"27\" class=\"wp-image-9737\" style=\"width: 27px;\" src=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/15.png\" alt=\"\">&nbsp;are the two-sample variance, and <img loading=\"lazy\" width=\"22\" height=\"25\" class=\"wp-image-9738\" style=\"width: 22px;\" src=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/16.png\" alt=\"\">&nbsp;and <img loading=\"lazy\" width=\"29\" height=\"18\" class=\"wp-image-9739\" style=\"width: 29px;\" src=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/17.png\" alt=\"\">&nbsp;are the two-sample capacity.<\/p>\n\n\n\n<p>The paired sample t-test is a within-subjects design often used in experimental research, to test the differences in the data obtained by two groups of data obtained under different conditions. For example, compare whether there is a significant difference in the purchase intention of the sample in the context of advertisements and no advertisements. The formula for the paired t-test is:<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" width=\"143\" height=\"68\" src=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/18.png\" alt=\"\" class=\"wp-image-9729\" srcset=\"https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/18.png 143w, https:\/\/support.divominer.com\/en\/wp-content\/uploads\/2023\/04\/18-50x24.png 50w\" sizes=\"(max-width: 143px) 100vw, 143px\" \/><\/figure>\n\n\n\n<p>where dbar = mean difference, sd\/\u221an = standard error = standard deviation of the difference \/ sqrt of number of samples.<\/p>\n\n\n\n<p><strong>3. One-tailed or two-tailed t test<\/strong><\/p>\n\n\n\n<p>Based on whether you want to test the difference in a specific direction, there is one-tailed t-test and two-tailed t-test. A one-tailed t-test, also known as a directional t-test, is a statistical hypothesis test where the null hypothesis specifies that the mean of the population is either greater than or less than a certain value. Thus, the alternative hypothesis is that the mean is in the opposite direction. One-tailed t-tests are used when the researcher has a clear directional hypothesis or when it is only important to detect differences in one direction. A two-tailed t-test, also known as a non-directional t-test, is a statistical hypothesis test where the null hypothesis specifies that the mean of the population is equal to a certain value. The alternative hypothesis is that the mean is either greater than or less than the null hypothesis value. Two-tailed t-tests are used when the researcher does not have a clear directional hypothesis or when it is important to detect differences in both directions. In practice, the choice of an appropriate t test depends on the research question, the available data, and the hypotheses being tested.<\/p>\n\n\n\n<p><strong>4. Perform t-Test on DiVoMiner\u00ae<\/strong><\/p>\n\n\n\n<p>On DiVoMiner\u00ae platform, click \u201cStatistical analysis \u2013 Advanced statistics \u2013 Create a calculation task \u2013 t-Test\u201d. More statistical tests will be released soon. Stay tuned!<\/p>\n\n\n\n<p><strong>5. References: <\/strong><\/p>\n\n\n\n<ul><li>Bevans, R. (2022, December 19).&nbsp;An Introduction to t Tests | Definitions, Formula and Examples.&nbsp;Scribbr. Retrieved February 27, 2023, from <a href=\"https:\/\/www.scribbr.com\/statistics\/t-test\/\">https:\/\/www.scribbr.com\/statistics\/t-test\/<\/a><\/li><li>Box, J. F. (1987). Guinness, Gosset, Fisher, and Small Samples.&nbsp;<em>Statistical Science<\/em>,&nbsp;<em>2<\/em>(1), 45\u201352. <a href=\"http:\/\/www.jstor.org\/stable\/2245613\">http:\/\/www.jstor.org\/stable\/2245613<\/a><\/li><li>Britannica, T. Editors of Encyclopaedia (2022, December 9).&nbsp;<em>Student\u2019s t-test<\/em>.&nbsp;<em>Encyclopedia Britannica<\/em>. <a href=\"https:\/\/www.britannica.com\/science\/Students-t-test\">https:\/\/www.britannica.com\/science\/Students-t-test<\/a> &nbsp;<\/li><li>Derrick, B., Toher, D., &amp; White, P. (2017). How to compare the means of two samples that include paired observations and independent observations: A companion to Derrick, Russ, Toher and White (2017).&nbsp;<em>The Quantitative Methods for Psychology, 13<\/em>(2), 120\u2013126.&nbsp;<a rel=\"noreferrer noopener\" href=\"https:\/\/psycnet.apa.org\/doi\/10.20982\/tqmp.13.2.p120\" target=\"_blank\">https:\/\/doi.org\/10.20982\/tqmp.13.2.p120<\/a><\/li><\/ul>\n","protected":false},"featured_media":0,"parent":9138,"menu_order":2,"comment_status":"open","ping_status":"closed","template":"","doc_tag":[],"_links":{"self":[{"href":"https:\/\/support.divominer.com\/en\/wp-json\/wp\/v2\/docs\/9720"}],"collection":[{"href":"https:\/\/support.divominer.com\/en\/wp-json\/wp\/v2\/docs"}],"about":[{"href":"https:\/\/support.divominer.com\/en\/wp-json\/wp\/v2\/types\/docs"}],"replies":[{"embeddable":true,"href":"https:\/\/support.divominer.com\/en\/wp-json\/wp\/v2\/comments?post=9720"}],"version-history":[{"count":6,"href":"https:\/\/support.divominer.com\/en\/wp-json\/wp\/v2\/docs\/9720\/revisions"}],"predecessor-version":[{"id":9741,"href":"https:\/\/support.divominer.com\/en\/wp-json\/wp\/v2\/docs\/9720\/revisions\/9741"}],"up":[{"embeddable":true,"href":"https:\/\/support.divominer.com\/en\/wp-json\/wp\/v2\/docs\/9138"}],"next":[{"title":"Create a new t-Test task","link":"https:\/\/support.divominer.com\/en\/docs\/divominer-user-manual\/advanced-statistics\/create-a-new-t-test-task\/","href":"https:\/\/support.divominer.com\/en\/wp-json\/wp\/v2\/docs\/9812"}],"prev":[{"title":"Create a new normality test task","link":"https:\/\/support.divominer.com\/en\/docs\/divominer-user-manual\/advanced-statistics\/%e6%ad%a3%e6%80%81%e6%80%a7%e6%a3%80%e9%aa%8c%e4%bb%bb%e5%8a%a1\/","href":"https:\/\/support.divominer.com\/en\/wp-json\/wp\/v2\/docs\/9807"}],"wp:attachment":[{"href":"https:\/\/support.divominer.com\/en\/wp-json\/wp\/v2\/media?parent=9720"}],"wp:term":[{"taxonomy":"doc_tag","embeddable":true,"href":"https:\/\/support.divominer.com\/en\/wp-json\/wp\/v2\/doc_tag?post=9720"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}