Do I need a comma after "given that" and "in absence of"?

Example sentences

  • Given that the survey is representative(,) the author still assumes that the 450 respondents are the majority of those surveyed.
  • In absence of this information(,) the author's conclusion is logically unpersuasive.

Questions

  1. Do I need to write a comma where I show "(,)" in these sentences above?
  2. Could you also tell me if there is a reason that can be generalized?

Solution 1:

In your examples, a comma is appropriate.

The first part of each sentence, before the comma, is a dependent clause because it contains a noun and a verb, but does not express a complete thought. The part after the comma is a main clause because it has a subject and verb and expresses a complete thought.

From the Purdue University Online Writing Lab

Use commas after introductory a) clauses, b) phrases, or c) words that come before the main clause.