With a couple of noted exceptions, the samples are to be run in an ordinary user schema, in almost all cases from SQL*Plus. For convenience, this user will be referred to as "samples" and should be created thus...

create user samples identified by samples;
grant resource, connect, ctxapp to samples;

• Quick Start
• The Text index schema objects
• Index Creation
• Index Response to DML
• Cleaning up the $P table (the $ORACLE_HOME/ctx/sample/util/drclnptb.sql script)
• Adding Stopwords to an existing index
• Queries (including thesaurus creation and output)
• Highlighting and Filtering
• Teaching The Text Query Expression
• Theme-based functionality
• Multilingual functionality
• Export and Import
• CTXSYS Data Dictionary Views
• The CTX_% packages
• Text Query Expression Reserved Words and Symbols