The Accuplacer Is Cheaper and Convenient
Since both college placement exams cover the same material under similar sections--including writing, reading comprehension and math--the choice between the Accuplacer or the THEA is a matter mostly of time, cost and format preference. The Accuplacer is the less expensive, untimed test that you can take over the computer at your campus's testing center. You get your Accuplacer scores immediately after you take the test. These factors make it the more attractive option for many students.
The THEA Is a Paper Test
If you are better at paper tests, you may prefer the THEA over the Accuplacer. The THEA is only available as often as once a month, is timed, is significantly pricier and is sent off for scoring, requiring a wait period for your results.
If time and money aren't obstacles, and you're better at paper tests, register for the THEA college placement exam. Otherwise, the Accuplacer may better fit your needs.