Tara,
The ladies are doing such a great job of helping you talk through your options for testing. I thought I'd just chime in too.
For our older boys, we did the Iowa Basics Skills Test for many years. We did do all the portions, and I tested my boys yearly simply because I wanted to be sure we were covering all of our bases. Our boys did outstanding on the tests in all areas including science and social studies.
By the time we had four boys in school needing testing, due to time constraints and multiple kiddos to test, I switched to the CAT test. We did it through Seton. We also switched to the CAT Core Battery/Survey Edition to make the testing even shorter. My boys did very well on the CAT Survey also ending up in the 98th-99th percentile with the older boys having very similar scores to those they had gotten on the Iowa Basics Skills Test. I was thrilled with the shorter test time!
In comparing the two tests, I would say that the CAT Survey is much shorter time-wise to give to your child. This means it also has fewer questions. With fewer questions, each question a child misses has a greater impact on his/her score. The CAT Core Battery/Survey only focuses on the core areas of reading-related skills, language arts/grammar, and math. It does include grammar parts of speech, where the Iowa Basics Skills does not specifically include parts of speech. At the younger levels, specifically grades 2 and 4, the CAT Survey doesn't seem to be written in as grade-specific a way, making the test questions seem all over the map as far as level of difficulty goes. This may have been corrected in the new Terra Nova 2/CAT 6. At the upper levels of the CAT Survey, this is less of a problem and the test seems to level out. The CAT does not require any credentials by the instructor in order to administer.
I have not given the new Terra Nova 2/CAT 6.
The Iowa Basics Skills Test definitely takes longer to complete and includes many more questions. This can be a good thing though, as each question the child misses has less of a negative impact on his/her overall score. The Iowa test is more grade specific, making the questions feel more grade appropriate. There are also more questions for each subject areas tested giving a better overall picture of the child's performance. I felt the Iowa Test gave me a better picture of where my kiddos were at in each area. The Iowa Basic Skills Test requires you to be approved as a tester in order to give the test. Proof of a bachelor's degree is required, and you can be approved as a tester through BJU or through Seton and also order the test through them too. You can see a comparison of the various tests here (if you click on the tab that says "Standardized Test Comparison Chart"):
http://www.setontesting.com/testing-products/
One thing you could consider would be to give only the reading-related, language, and math portions of the Iowa Test. This would help lessen the time required to test and would work if your state does not require all portions to be given. Our state has now moved toward only requiring the reading, language, and math portions. Math computation has also typically been an optional part of the Iowa Test as well. Usually there is a sticker on that portion of the test identifying it as optional. I found the timed math computation part of the test was the only timed test that stressed my boys out. So, we later omitted it since it was optional. The rest of the test seemed just fine. The research section of the Iowa Test used to be labeled as optional too.
Grades K-2 of the Iowa Tests are untimed, which is wonderful for those little ones! Otherwise, you could consider giving the old CAT or the new Terra Nova 2/CAT6 doing either the Complete Battery or the Survey. A test comparison chart is here:
http://www.setontesting.com/pdf/TerraNova.pdf
Either test will work. We typically test over multiple days at our house, doing only 2 tests in one sitting (or 3 shorter ones). With the CAT Survey test we only did one test session each day. When we did the CAT longer battery or the Iowa Test we sometimes did two testing sessions a day - one in the morning and one in the afternoon.
We give the test after the boys are well-rested and fed. We take a brief break in between the tests to go to the restroom and have a drink of water. We make sure it is quiet while we are testing. We pray before we test and try to give the test in a well-lighted, calmer area of our home. I set the timer, but I place it on a counter or on an area further away from where they are working rather than placing a timer right on the table in front of them that they are constantly seeing. They can definitely refer to the timer, and I warn them at the halfway mark of the time, and again as we get closer to the time being up; but we try not to make the time their focus. It is wise to pay attention to see that your child has not skipped filling in a bubble or has not filled in two bubbles on the same line as they take the test, as this can make the child be off one line all the way through the test. We were told to circulate and watch for this in the public school classroom as well as this is very traumatizing to children. I think your child will do just fine!
Testing at home is a friendlier environment than testing at school!
Blessings,
Carrie