combas.blogg.se

How to calculate confidence interval in spss 16
How to calculate confidence interval in spss 16





how to calculate confidence interval in spss 16

In the dialog that appears, put "Tip_Percentage" in the "Test Variable(s)" window and "Condition2" into the "Grouping Variable" window: To access the test, select Analyze → Compare Means → Independent Samples T Test. Now that you have satisfied the capricious whims of the trolls, we can proceed to analyze the data. You can see how the string variable has been recoded as 1s (for chocolate) and 2s (for no chocolate): In Variable View, click on the "Values" cell in the "Condition2" row (highlighted below): You can check out the results in the Data Window, both in Data View and Variable View. That last step is handy in case your data includes any missing values. In the dialog that opens, move "Condition" into the "Variable -> New Name" window, type "Condition2" in the "New Name" field and click "Add New Name", check the box labeled "Treat blank string values as user-missing". Luckily, there is a (somewhat) easy workaround. "Hey!" you shout, "I’ve already got my data entered as strings!" I know, I know.

how to calculate confidence interval in spss 16

They decreed that all independent variables must be coded as numbers, not string variables. You see, the creators of SPSS were evil troll-like creatures who delighted in inconveniencing beginning statistics students. Plotting the data is a good way to get a feel for differences between groups, but statistics can provide us with two more pieces of information: a confidence interval for the difference between means and a measure of the probability that an effect is due to chance (statistical significance).īefore we can get started with our statistical analysis, we need to take care of something.







How to calculate confidence interval in spss 16