MAXQDA allows for changes in variable types for existing variables:

• Document variables, which display how often a code exists (their source is acknowledged as “code”) can be transformed into a binary variable by clicking on the  button. After it is transformed the variable only contains the values 1 and 0, stating if a code has been assigned in this document or not).
• User defined variables “Integer,” “Floating Point,” “Date/Time” and “Boolean” can be transformed into text variables by clicking the .

Transforming a variable to binary or string cannot be reversed.