Introduction

1. Goals
The online tutoring class provides an efficient way to train the QOCA user to master the requirements, procedures, and strategies of running QOCA. It also provides useful materials for those who are not QOCA users but are interested in the performance of the software. The information highway blurrs the boundary between user and lecturer. Users can learn from each other, teach each other and help each other. This online tutoring class tries to embody such a style. We encourage web page readers to make comments and suggestions to improve our work.
How do we guarantee the quality of the training? We plan to set up an online QOCA examination. Due to manpower shortage, however, we have been unable to finish the online exam at this time.

2. How to learn the online tutoring class?
The online tutoring classes are divided into two categories: basic and advanced. The basic classes teach you the necessary skills to run QOCA main software and utilities, to prepare drive files, to make the plots, and to obtain the tectonics results. The advanced classes teach you how to manipulate the various constraints, how to deal with dirty data, how to catch the outliers efficiently, how to choose the coseismic and postseismic models, and how to get the realistic statistics.
Every class is relatively independent so that users can jump to any class based on their current knowledge and skill. We recommend that users begin with the basic classes before jumping to the advanced classes. In each class, there is a brief introduction which outlines the function of this step. Please read the introduction and look at the template of the relevant files first. Then try the virtual run, which is not a real run but displays the screen output from a real run. Finally, look at the templates of the output files.
The classes only teach you how to run the software. If you want a deep insight into the theory, mathematics, and the design of the software, please look at the "Theory" directory of the web page or read the paper of Dong et al., 1998.

3. How to report a problem?
There are two ways to help resolve you may encounter. First, you can post your problem in the "Help board" page. All the previously posted problems (including answers, suggestions) are listed in the "Help board posters" page. Your posted problem will be open to the public so that every user can potentially help you. Second, send e-mail to me by clicking my name (Danan Dong) on the left side of the page ("Online classes" frame). I will try to figure out your problem. We encourage you to use the first approach, which is more efficient and will help more users.

4. Basic requirements
QOCA was developed under the UNIX system. Currently, the SUN, HP and Linux versions are available. We prefer that users know the UNIX operational system and have basic C-shell experiences.

Thanks for your patience and for reading the introduction to its end. Are you ready to try the QOCA class? Let's go. Have fun!