Regarding the U of Washington comparison report - thanks, I haven't seen that clearly biased report before. They obviously find that Singapore Math is better in all regards, but they can't seem to bring themselves to state that categorically. Of course, the study was funded by the NSF and the lead currently works on teacher training in these new methods.

You commented on many of the same things I saw in the reoprt, but I want to make a couple of my own. In the conclusion section, they refer to the TIMSS tests:

"... Of course, if the TIMSS tested rote memory, recall of facts, and manipulation skills, Singapore students would have an edge over American students; their curriculum emphasizes practice problems and makes sure that the students attain fluency and computational skills at a level which we judge to be one to two grades higher than their American counterparts. However, the TIMSS tests were designed to test understanding of concepts in addition to competency. The inferences that can be made thus become more murky. ..."

Murky? It's very clear to me. One to two grade levels ahead AND they do well on understanding concepts? Golly. They just can't understand why this is happening. They can't understand how fluency and computational skills in the basics forms the foundation for all conceptual understanding?!?

Then, a more telling comment:

"... On the other hand, we doubt very much that any tests no matter how well designed can accurately test creativity and independent thinking, qualities which the new American curricula, such as CMP and MIC, strive to foster. ..."

I had a programmer working for me who wrote some code once that was independent and creative, ... and wrong! He didn't research the literature and was reinventing the wheel incorrectly. Do the people who support CMP and MIC really believe that fluency in the basics prevents creativity and independence? The opposite is true.

One of their final biased comments is:

"... We have found much to like in the new American curricula, especially their emphasis on conceptual understanding and on educating independent thinkers, qualities we value in our society. ..."

"Conceptual understanding"? The TIMSS showed that the Singapore students had far better conceptual understanding than the American students, but they found that result "murky". (not to their liking) The American curricula emphasizes conceptual understanding, but it apparently doesn't work.

CMP uses this report to support their curricula????? Incredible! One or two grade levels behind and it doesn't provide the same level of conceptual understanding as the Singapore curricula. What's left? "Creativity" and "independent thinking"? What do they mean? How to do math without knowledge and skills?

Our town uses MathLand followed by CMP for grades 5-8. It is understood by many parents that they have to supplement or tutor their kids to make sure that they are ready for college prep math in high school. Other parents have long ago taken their kids out of public school. It is one thing if public schools want to set lower standards, but please don't tell me that they are really higher or better standards. One or two grade levels!!! Don't tell me that the CMP and MIC students are somehow going to magically catch up and pass the Singapore students with their creative and independent thinking. They better hope that there isn't a test for these qualities. I am sure that the Singapore students would surpass the American students in those categories too. Murky, my foot!

A comparison of math teaching methods by people who can draw pretty graphs, but obviously lack the mathematical competence to draw conclusions from them...

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shown as starting out at just a hair above the 7th grade level, but at the end of the school year has shot up to end up two-thirds the way to 9th grade!
We want to know what math program they were using!
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Remember, this wasn't longitudinal - it's likely that many of the students in the fall/spring sample were using different of math programs.

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starting out at just a hair above the 7th grade level, but at the end of the school year has shot up to end up two-thirds the way to 9th grade!
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Two thirds of nine is... ;)

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when the data really doesn't show much improvement at all, they trumpet, "See? It's just as good!"
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In fairness to Ridgeway et al, you ignored the purpose (and bulk of evidence) of their work: They did not set out to prove greater gains in basic skills, just that problem solving skills could be developed without sacrificing "basic skills" (and Steve already pointed out that it makes sense for these general aptitudes to develop together).

And they did provide some evidence that CMP improved problem solving in areas such as algebra and geometry (8th graders should know this stuff) without any detriment to operational skills in comparison to the non-Cmp students.
Of course, not all control groups are equal...

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shown as starting out at just a hair above the 7th grade level, but at the end of the school year has shot up to end up two-thirds the way to 9th grade!
We want to know what math program they were using!
---
Remember, this wasn't longitudinal - it's likely that many of the students in the fall/spring sample were using different of math programs.

---
starting out at just a hair above the 7th grade level, but at the end of the school year has shot up to end up two-thirds the way to 9th grade!
---
Two thirds of nine is... ;)

---
when the data really doesn't show much improvement at all, they trumpet, "See? It's just as good!"
---
In fairness to Ridgeway et al, you ignored the purpose (and bulk of evidence) of their work: They did not set out to prove greater gains in basic skills, just that problem solving skills could be developed without sacrificing "basic skills" (and Steve already pointed out that it makes sense for these general aptitudes to develop together).

And they did provide some evidence that CMP improved problem solving in areas such as algebra and geometry (8th graders should know this stuff) without any detriment to operational skills in comparison to the non-Cmp students.
Of course, not all control groups are equal...

Chris, thank you for your excellent comments and eagle eyes.

A few points of clarification are in order. I wrote:

Note that the three graphs do not represent longitudinal data, meaning that the 6th, 7th and 8th grade students tested are actually three different groups of students.

Regarding your second point, I lost my calculator, so I cannot compute two-thirds of nine. ;-)

And your third point is a valid one. Yes, they had a lot of data to demonstrate how well these students scored on some new test that measures "problem solving skills" (without sacrificing basic skills) which was the point of their study. I simply find their data very suspicious.

Many school districts which have whole-heartedly embraced CMP for their entire middle-school math curriculum have been rewarded by plummeting math scores.

I'm more concerned with the real-world effects of any new program than with the numbers the program designers present in support of their case. It certainly doesn't help their case that the numbers they present here are eyebrow-raising.