To create a schema you can use Roma. This gives you a graphical interface that allows you to include or exclude elements, include or exclude attributes, and constrain values for attribute values.

A few pointers for using Roma…

• hit submit every time you make a change. there is a bug that sometimes it doesn’t look like you’ve saved your changes, but in reality you have. and if you don’t hit save, then you’ve definitely not saved your work.
• give your schema a name that will help you understand what its purpose is for. you can also supply a description of its purpose. one idea is to create a schema and then come back later and modify it as you delve deeper into analyzing your text.
• save your schema as Relax NG schema (compact syntax). this files gives your xml code a place to go to double check that you are organizing your data properly.
• save your documentation in html so that you can read what the elements and attributes you can use in your customized schema are.
• save your customization (aka the ODD file). this is the file that creates the schema (ie .rnc file). if you have any problems with your schema you might want to look at the ODD file to make sure the changes you made are properly reflected in the schema document.

creating a schema allows your coders to reduce the options they can choose from and hopefully reduce the amount of mistakes they can possibly make.