Dear Prof. Raiesi,

If you have several groups for example 4 groups as A B C D. You should compare A with B, A with C, A with D, then B with C, B with D and Finally C with D. This analysis could perform by ANova test with spss software or grafpad prism. Of course you can do it with tukey pairwise test that this test is a complementary test for ANova test.

Best Wishes

Amin

Dear Prof. Raisi,

You may find complete step wise explanations of performing your test in STATISTICA via following link:

http://documentation.statsoft.com/STATISTICAHelp.aspx?path=BasicStats/BasicStatistics/Examples/Example2BreakdownsandOneWayANOVA

Bests, Bahar 

Dear Fayez,

Pairwise comparison in available in SPSS under Analyze > Compare means > One way ANOVA and the Post hoc tests button.

Have a look at out worksheet:

Technical Report One-Way Analysis of Variance (ANOVA)

Dear Prof. Raisi

You can do it using Excel also. At first please check the main menu-bar at top of your work-sheet for finding "Data". Click on "Data" then check the right part of main menu. You may be see "Data Analysis" at the most right section.

(If "Data analysis" isn't visible so you can make it visible using the following steps):

Please click on:

1-File

2- Options-(here you will see a new window, in new window click on Add-Ins), at the bottom of window you will see "Manage Excel Add-Ins and an Icon "Go". When you click on "Go" another new window will be appeared.

3- Please mark all options and then click on "Ok".

By use of these steps you will setup "Analysis Data" and it will be possible to do T-test and other data analysis options easy.