{"id":483,"date":"2015-07-16T08:55:40","date_gmt":"2015-07-16T12:55:40","guid":{"rendered":"http:\/\/sites.berry.edu\/vbissonnette\/?page_id=483"},"modified":"2021-05-08T14:18:13","modified_gmt":"2021-05-08T18:18:13","slug":"t-test-for-dependent-groups","status":"publish","type":"page","link":"https:\/\/sites.berry.edu\/vbissonnette\/index\/stats-homework\/documentation\/t-test-for-dependent-groups\/","title":{"rendered":"T Test for Dependent Groups"},"content":{"rendered":"

Example homework problem:<\/h3>\n

Twelve people completed a difficult hand-eye coordination task twice: once in a quiet room, and once in the same room while loud rock-and-roll music was being played. The order in which subjects experienced these conditions was counterbalanced: half performed in the\u00a0 quiet environment first, half performed in the loud environment first.\u00a0The researcher measured the number of errors committed by the participant while performing. Thus, the lower the score, the better the performance. Here are the results:<\/p>\n\n\n\n\n\n
Participant:<\/td>\n1<\/td>\n2<\/td>\n3<\/td>\n4<\/td>\n5<\/td>\n6<\/td>\n7<\/td>\n8<\/td>\n9<\/td>\n10<\/td>\n11<\/td>\n12<\/td>\n<\/tr>\n
Quiet Environment:<\/td>\n14<\/td>\n21<\/td>\n24<\/td>\n16<\/td>\n18<\/td>\n20<\/td>\n15<\/td>\n20<\/td>\n17<\/td>\n16<\/td>\n19<\/td>\n12<\/td>\n<\/tr>\n
Loud Environment:<\/td>\n21<\/td>\n22<\/td>\n21<\/td>\n19<\/td>\n18<\/td>\n25<\/td>\n17<\/td>\n18<\/td>\n21<\/td>\n24<\/td>\n21<\/td>\n15<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Was there a significant difference in performance between the two treatment conditions\u00a0 (alpha = .05)?<\/p>\n

If you would like help with the hand-written solution to this problem, click here<\/a>.<\/p>\n

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Enter these data into the first two columns of Stats Homework’s <\/i>data manager and rename the variables. Your screen should look like this:<\/p>\n

\"dttest3\"<\/a><\/p>\n

Make sure to double-check and save your data. To conduct your analysis, pull down the Analyze<\/b> menu, choose Tests for One or Two Samples<\/b>, and then choose T Test for Related Samples<\/b>. Here is the user dialog for this procedure:<\/p>\n

\"dttest4\"<\/a><\/p>\n

Move the two variables to the two blanks on the right, and then select all your output options.\u00a0 Then,\u00a0click the\u00a0Compute<\/strong> button.<\/p>\n

Here is the basic output:<\/p>\n

\"\"<\/a><\/p>\n

 <\/p>\n

Descriptive Statistics<\/b>. Basic summary and descriptive statistics are presented for both variables and for the difference scores. Also, these difference scores have been written to your data. For a guide to these statistics, see the documentation page for the explore procedure<\/a>.<\/p>\n

Inferential Statistics<\/b>. This table lists the results of your t <\/i>test:<\/p>\n