What is the difference between mail merge and document assembly? This is a common question and one that has no single answer because both have features that overlap.

Mail Merge

Mail merge is a process of producing multiple (and potentially large numbers of) documents from a single document template and a structured data source. This technique is typically used to create personalised letters and pre-addressed envelopes or mailing labels for mass mailings from a database mailing list of names and addresses.

The procedure of mail merging is typically carried out using a word processing program. The template is a word processing document which contains fixed text, which will be the same in each output document, and variables, which act as placeholders that are replaced by text from the data source. The data source is typically a spreadsheet or a database which has a field or column matching each variable in the template. When the mail merge is run, the word processing system creates an output document for each row in the database, using the fixed text exactly as it appears in the template, but substituting the data variables in the template with the values from the matching columns.

This technique of merging data to create mail shots gave rise to the term mail merge.

Document Assembly (Mail Merge)

Document Assembly (Mail Merge) also produces a document or documents from a structured data source but is more likely to produce a single document. Document Assembly (Mail Merge) differs from Mail Merge in that the data is usual collected from the user through an interview process. This interview process is usually conducted using forms that guide the user through a series of questions. These questions in turn will provide the values for substitution in the document template variables.

Interview form in WordFusion



In addition the interview process or form can apply formatting, validation and other rules that depend on the values entered by the user. When the interview process is completed the answers collected are used in the assembly (Mail Merge) process. When the assembly (Mail Merge) process is run the software may also run a further round of validation and substitution when assembling the information collected into document variables. A good example of this is applying a substituting a gender variable for other values during the document assembly (Mail Merge) process.

Example; if a field called gender has a value of male it is possible to substitute different occurrences of that field in a document with the values contained in a MergeText list such as he, his, him etc, see below.

Using MergeText this example could be assembled as.
<> wallet was stolen. <> was upset.
His wallet was stolen. He was upset.

Summary

Mail Merge is mostly used to automate the creation of multiple documents from a data source. While document assembly (Mail Merge) is primarily an interview driven process that collects information in an interactive process and applies rules to the data before the document assembly (Mail Merge) process occurs.