I think one of the wonderful things about homeschooling is that you can tailor your days to the needs of your kids.  I used to be a school teacher and I am 100% against standardized testing. I believe that we should follow our kids progress and evalute where we can reinforce certain learning goals.

It's sort of a trick question because "standardized testing" refers to a lot of things. If you're meaning the state tests designed to measure progress largely for the purpose of NCLB purposes, that's a very different answer than if you're referring to other assessments which have standardized procedures for administration and normative data attached.

If you're referring to the latter, the issue is what other types of assessment procedures the family would use to more thoroughly understand the academic needs of the child. Typically, the opposite of "standardized" assessment would be informal assessments, which can provide helpful information on a day-to-day basis, but which lack validity and reliability for understanding overall progress toward instructional goals.

Honestly, I use a standardized test to report my children's progress to the State each year because it is less trouble than a portfolio.  However, my kids are like me and very good at this type of test without out having to prep for it.  Which is one of the failings of standardized tests.  Some people are just better at taking them than others. I don't think anyone, homeschooled or not, should have to use standardized tests for assessment.  The results are often misleading since they can't measure the higher levels of learning comprehension.

Our state requires them 3rd, 5th, & 7th grades. Although homeschooling parents likely aready know how their children are progressing some of these types of tests are helpful as a "double check" for parents. My daughter took one for the first time this year. The subjects she scored only average (and slightly below) in were the areas I already knew we were going to need more focus on at some point.

Also, depending on what test you use, additional IQ testing and learning styles tests can be helpful in knowing how to gear learning experiences in ways that best suit your child - one main reason why many homeschool to begin with. We used the Iowa Tests and Iowa CogAT; combined the results were very helpful to us.

Last point, if your child is going to go  to college the "skill" of taking such tests is important. We plan on having our children take them even on years not required by our state just for the practice. So when they get to the point of taking tests like SATs they will not be at a disadvantage in that area.

There are definitly days I wish we had more testing at home, mainly because I doubt my abilities to teach well, and wonder how much information she retains at the end of the day. It comes out in conversations she has with others, but to have something concrete that I could put in a folder would be nice, but I dont want to teach for a test either..lol

I homeschool and I use the assessment tests to see where my child may need a little more practice.  They are not required by my state but I have peace of mind knowing that he is above the "standard" and fluent.