E-Prime data files may be merged to create E-Prime merged data files. When data from more than one session of data is combined into a single file, it is referred to as a merged data file. The process of merging involves selecting one or more E-Prime data files and performing a merge operation to combine the data from those files into a target file. Both single session data files and merged data files may be merged into other files (i.e., may be selected as source files). Single session data files may not be named as target files because they may contain only one session of data (i.e., data may not merged into them).