[PathOfEclipse]

This is especially true of teacher's unions, who have been openly hostile towards any meaningful way of measuring teacher performance, and have made it astronomically expensive to fire any teacher no matter how bad or incompetent. The world would be a much better place if teacher's unions didn't exist.

[andrepd]

How do you measure teacher performance? Have you looked at the actual proposals? They're atrocious, as if education needed to be any more of a rat race of chasing idiotic """performance""" metrics.

[PathOfEclipse]

If you read this book, there's a whole chapter dedicated to someone successfully coming up with a metric and validated it: https://www.amazon.com/Race-Bottom-Uncovering-Destroying-Edu...

The short answer is you measure student progress over time via standardized testing. Someone was able to obtain anonymized per-teacher data via FOIA request and verify that some teachers perform consistently and significantly better than others in terms of helping their students progress, and that this performance was stable across time and even when teachers moved to different schools. At one point, schools were required to provide this data until the law was successfully repealed at the behest of teacher's unions.

Teacher's unions pay mainly based on seniority, but this same data showed that, after about 5 years, teacher performance didn't really improve much. The unions also pay more for higher degrees, but there was no association found between higher degrees and teacher performance.

The book also discusses how different types of testing have been shown to be strong predictors of both future academic and professional success. You should not be so dismissive of objective numeric testing, whose results can be tracked and compared over time. No metric is perfect, but just about any metric beats that of the unions, who, in one area, had 99.8% of their teachers rated as "proficient". The union's metric is useless, and that is a feature for them, not a bug.

[eesmith]

If the grades given by unionized teachers is a better prediction of future academic and professional success than standardized tests, would you switch your support to unionized teachers over testing?

See, the thing is, high school GPA is a better predictor for academic success than standardized testing. Here are four quotes from the many relevant papers found through Google Scholar:

1) "Decomposing GPA: Why Is High School GPA the Best Single Predictor of First- Year GPA?" https://www.researchgate.net/profile/Jeffrey-Steedle/publica... :

> Research has consistently shown that high school grade-point average (HSGPA) is the best single predictor of academic outcomes in the first year of postsecondary education (Bowen, Chingos, & McPherson, 2009). Given that HSGPA is not a standardized measure of academic achievement—and is not therefore perfectly comparable across students or high schools—it likely incorporates information about college readiness beyond academic knowledge and skills.

2) "Does the ACT Composite Score or High School Grade Point Average Provide a Better Prediction of Bachelor Degree Attainment?" https://scholarworks.harding.edu/cgi/viewcontent.cgi?article...

> Results indicated high school GPA to be a significant predictor of persistence to degree attainment while the ACT Composite score was not a significant predictor. Implications from this study suggest that admissions officers may want to emphasize a student's high school GPA in determining if the student will complete a bachelor's degree program.

3) "High School GPAs and ACT Scores as Predictors of College Completion: Examining Assumptions About Consistency Across High Schools" https://journals.sagepub.com/doi/pdf/10.3102/0013189X2090211...

> High school GPAs (HSGPAs) are often perceived to represent inconsistent levels of readiness for college across high schools, whereas test scores (e.g., ACT scores) are seen as comparable. This study tests those assumptions, examining variation across high schools of both HSGPAs and ACT scores as measures of academic readiness for college. We found students with the same HSGPA or the same ACT score graduate at very different rates based on which high school they attended. Yet, the relationship of HSGPAs with college graduation is strong and consistent and larger than school effects. In contrast, the relationship of ACT scores with college graduation is weak and smaller than high school effects, and the slope of the relationship varies by high schoolYou write "objective numeric testing", but tell me, what is the objective reason those tests tend to focus on math and short-form English comprehension? Why do they omit art appreciation, musical skills, physical education, essay writing, and other topics that students learn at school?

4) "What Matters Most for College Completion?" https://www.calstate.edu/apply/Documents/elevating-college-c...

> Both SAT or ACT scores and high school GPA are associated with the likelihood that students at four-year colleges earn a bachelor’s degree. But when considered together, the predictive power of high school GPA is much stronger. Figure 2 shows that, among students with similar SAT or ACT scores, those with higher high school GPAs are much more likely to graduate. But among students with similar high school GPAs, no strong relationship exists between SAT or ACT scores and graduation rates (except that those who score below 800 are noticeably less likely to complete college).

> This makes sense given that earning good grades requires consistent behaviors over time—showing up to class and participating, turning in assignments, taking quizzes, etc.—whereas students could in theory do well on a test even if they do not have the motivation and perseverance needed to achieve good grades. It seems likely that the kinds of habits high school grades capture are more relevant for success in college than a score from a single test.

> ... And the relatively weak predictive power of SAT or ACT scores vanishes entirely once the student’s high school is taken into account, suggesting that the test scores serve partly as a proxy for high school quality.

Sure, you can claim I'm cherry-picking. But the same holds for the book you pointed to. And given just how many papers there are which argue that GPA is more predictive than standardized scores, it's certainly nowhere near as clear-cut as you appear to believe.

Does this start to make you reconsider your opposition to unionized teachers now? If not, why not?

[PathOfEclipse]

You're conflating things together and missing the plot. I was comparing the teacher evaluations given by teacher unions to the evaluations of teachers based on student improvement over time on standardized tests. You, on the other hand, changed the subject slightly, which is fine, but then you use the phrase "grades given by unionized teachers", which makes no sense. All the studies you cited talk GPAs in general. Whether the teachers doing the grading are unionized or not is not mentioned or relevant. If you're going to have a discussion, you should take care to use more careful language. It looks like you're trying to be deceiving in order to prop up teacher's unions.

I clicked on your first study and it doesn't even do any analysis on GPA as a predictor of future success relative to other standardized tests. In fact, it assumes this as true and then tries to explain why. It also looks like a low-quality paper published at conference without peer review.

I clicked on your second link. It's not peer reviewed. It only examines data from one university. It has a very small sample size. It has zero citations. It reaches conclusions that are contrary to existing literature. It does not look like it should be taken seriously.

I decided at this point to stop wasting my time. If your first two citations are so weak, I don't have much confidence in the others.

[eesmith]

> I was comparing the teacher evaluations given by teacher unions to the evaluations of teachers based on student improvement over time on standardized tests.

Wait. You were comparing the evaluations of teachers based on how teacher unions ranked them, compared to the evaluation of teachers based on the standardized test scores for their students?

How is that at all useful?

Why are teacher unions ranking teachers? How does that affect anything? How are standardized tests - which aren't designed as a measure of teacher effectiveness - at all relevant, and not full of noise?

We know methods like VAM (Value-Added Models) are extremely easy to misuse - so easy the American Statistical Association points how how it's difficult to apply them to ranking teacher effectiveness (see https://www.amstat.org/asa/files/pdfs/POL-ASAVAM-Statement.p... ). Why should I believe this book you cite - which seems to be written by a journalist and not a statistician - does a good job of it?

> then you use the phrase "grades given by unionized teachers", which makes no sense.

That's because I didn't understand what your argument was. The usual argument is "teachers unions mean teachers are bad at their jobs so we can't trust their judgement and GPA. Instead, we need to look to standardized tests." That's the argument I thought you were making.

> it doesn't even do any analysis on GPA as a predictor of future success relative to other standardized tests

No, it doesn't. It does give the citation: Bowen, Chingos, & McPherson, 2009 . But https://www.degruyter.com/document/doi/10.1515/9781400831463... is behind a paywall.

If you want to argue that the summary of the citation I gave is a poor interpretation of the research, then go ahead. But then I can say that your summary of the book you read is also wrong.

A book which I also cannot read.

And which does not appear to be peer reviewed.

> It's not peer reviewed. It only examines data from one university.

Thing is, the second link also gives citations to other research.

] If standardized testing is not as reliable a measure of student success, as proposed by the researchers previously cited ... Hodara and Lewis (2017) concluded that HSGPA was a better predictor of college performance than standardized exam scores, especially for students who enter college within a year of completing high school.

These are not meant to be read in a vacuum, but as an indication that the certainty you state is far from established.

[PathOfEclipse]

It seems like you're not at all understanding what I've been saying. The measure of teacher performance was based on student improvement over time on standardized tests. It is incredibly valuable to measure a teacher's capability in actually helping students learn and improve. After all, isn't that the sole purpose of teaching?

> That's because I didn't understand what your argument was. The usual argument is "teachers unions mean teachers are bad at their jobs so we can't trust their judgement and GPA. Instead, we need to look to standardized tests." That's the argument I thought you were making.

Yes, and we've also gone pretty far off-topic from what I was originally talking about at this point.

> No, it doesn't. It does give the citation:

Then why not lead with that citation and not the very weak conference paper that you chose to lead with?

Anyways, you may be right about GPA currently being a better predictor of academic success than the ACT. But, as this article explains: https://www.jamesgmartin.center/2020/02/gpa-or-sat-two-measu...

"In an extended version of their essay, Kuncel and Sackett acknowledge that GPA is the best predictor of student success, but they add: “Even better prediction is obtained by the combination of test scores and high school grade point average.” “Human behavior is notoriously difficult to forecast,” they write, “it would be strange for a single predictor to be the only one that matters. So it is also valuable to consider, whenever possible, how predictors combine in foretelling student success.”

If I were to further research this subject, I'd probably start with this book: https://www.amazon.com/Measuring-Success-Testing-College-Adm...

"Although the test-optional movement has received ample attention, its claims have rarely been subjected to empirical scrutiny. This volume provides a much-needed evaluation of the use and value of standardized admissions tests in an era of widespread grade inflation. It will be of great value to those seeking to strike the proper balance between uniformity and fairness in higher education."

Edit: also found this article interesting: https://www.latimes.com/california/story/2019-12-22/grades-v...

One person is quoted as pointing out that an advantage using the SAT is that it can help combat grade inflation because it looks bad to have a really high GPA but really low SAT score. It's also been shown over time that the average GPA keeps going up while SAT scores are flat or declining. Grade inflation is a major problem, and the use of standardized test does help with it.

[FireBeyond]

What might make for sensible, objective teacher metrics?