Run-ons

Consider these two independent clauses:

The evidence is incomplete.

More work needs to be done.

When two independent clauses are joined only by a comma,

                    The evidence is incomplete, more work needs to be done.

by a transitional word or phrase,

                   The evidence is incomplete therefore more work needs to be done.

or by nothing at all,

               The evidence is incomplete more work needs to be done.

the result is a run-on.

To repair, the two independent clauses must be

• joined by a coordinating conjunction (and but or for nor so yet) followed by a comma,

                                 The evidence is incomplete, and more work needs to be done.

• separated by a semicolon,

                                The evidence is incomplete; more work needs to be done.

• or divided into two sentences.

                             The evidence is incomplete. More work needs to be done.