https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/IML-functions-in-group-sequential-design/m-p/72623#M452 I think you'll find section 4.2.8 of the book "Analysis of Clinical Trials Using SAS: A Practical Guide" (Dmitrienko,A., et. al., Cary,NC:SAS Institute, 2005) helpful. Tue, 22 Sep 2009 19:57:58 GMT StatDave 2009-09-22T19:57:58Z https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/IML-functions-in-group-sequential-design/m-p/72622#M451 I am working on 'Interim Data monitoring' in clinical trials,and found that IML is a powerful tool to compute the stopping boundaries with the function SEQ and SEQSCALE,but I can not understand the elements of these function.<BR /> I used to refer to the 'SAS/IML user's guide',but there are no examples,and I can not catch the meaning.<BR /> So,I want to know if there are some material related to the functions,ideally containing some examples.<BR /> Thank you very much! <span class="lia-unicode-emoji" title=":slightly_smiling_face:">🙂</span> Tue, 22 Sep 2009 07:30:57 GMT https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/IML-functions-in-group-sequential-design/m-p/72622#M451 deleted_user 2009-09-22T07:30:57Z https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/IML-functions-in-group-sequential-design/m-p/72623#M452 I think you'll find section 4.2.8 of the book "Analysis of Clinical Trials Using SAS: A Practical Guide" (Dmitrienko,A., et. al., Cary,NC:SAS Institute, 2005) helpful. Tue, 22 Sep 2009 19:57:58 GMT https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/IML-functions-in-group-sequential-design/m-p/72623#M452 StatDave 2009-09-22T19:57:58Z https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/IML-functions-in-group-sequential-design/m-p/72624#M453 Thank you so much,your reply is very helpful~ Wed, 23 Sep 2009 00:46:53 GMT https://communities.sas.com/t5/SAS-IML-Software-and-Matrix/IML-functions-in-group-sequential-design/m-p/72624#M453 deleted_user 2009-09-23T00:46:53Z