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Adding Student Growth to the Achievement Index; Norm-referencing vs. Criteria-referenced benchmarks

Release Date: 

May 8, 2013

As we continue to do outreach as a staff, we’ve heard a recent uptick in comments and concerns about the norm-referencing that occurs in the Student Growth Percentiles (SGP) methodology which is at the heart of the revised Index proposal.  Recently, stakeholders – through our AAW feedback process, through WSSDA regional meetings, and most recently, through our conference call with ESD superintendents – have asked questions about why the move toward norm-referencing, instead of an alternative means of measuring student growth that sets objective standards of year-to-year growth.  After all, it seems we are less concerned with whether your growth is “above average,”; what we really care about is whether you are getting the academic growth you need to be successful — to be, in that famous phrase, “college and career-ready” by the time you exit high school.

For what it’s worth, I agree!  Criteria-referenced standards of growth are important, and it’s important to remember that SGP has some (remember our discussions of “adequate growth?” – see video at link)  But remember, there are two key considerations; first what we want for our system, and second, what is possible now versus what we may have to consider for inclusion in the future.  This latter consideration is significant when it comes to SGP.

So here are a few facts to arm yourself with as you speak with your colleagues about this issue – why SGP?

  • The WA state board of education is not proposing some new, risky methodology.   Keep in mind — we are not developing anything new.  We’re simply implementing an industry-accepted model for measuring growth.  It’s been in adopted in 20+ states around the country, has been approved repeatedly by the federal government, and has the blessing of some of our nation’s foremost authorities on student growth data.  It is particularly popular in states (like our’s) that lack year-to-year vertical scaling in their assessments.
  • The absence of vertical scaling in the testing system presents certain limitations.   Washington State’s choice for measuring student growth is shaped significantly by what type of testing system we have (and don’t have).  As we’ve gone over with Richard Wenning, and the video below reinforces (go to the 2:00 mark for this issue in particular), we are not currently equipped to simply subtract year to year changes in scale scores to derive growth rates.  However, a discussion about what criterion-referenced enhancements we could add after we have multiple years of data from a new set of vertically scaled SBAC-generated tests is a good conversation for us to have, and I expect we’ll have it.
  • The process of selecting SGP has been deliberative – over several years, involving both SBE and OSPI – To be clear, the process of scoping out various growth methodologies, vetting SGP, and generating SGP data for all 295 districts didn’t start this fall when the SBE started revising the Index.   The process started about 4 years ago.  Washington State was expected to begin development of student growth data as a condition of its first award of federal ARRA funding, right around 2009.  At that time, OSPI, with their national technical advisory committee, reviewed various growth methodologies, what their system would support, and arrived at SGP.  The consideration for the SBE this fall, then, was whether to build upon the growth system that was already under development in Washington, or try to break away from what was already in development and start something new solely for the index.  However, with less than a year to respond to USDOE, basically the same testing system in place, and above all else, a clear desire to align policies rather than create multiple methodologies: the choice was pretty clear —  stay the course, align, and implement what we’ve invested in.
  • SGP is not “standard-less”.   While it is true that SGP is primarily a norm-referenced system of growth, it’s important to note that it allows for a determination of “adequate growth.”  Remember, adequate growth is how much growth is required to get students to standard in 3 years.  But  SGP expresses the year to year gains necessary to achieve that standard in normative terms (student growth percentiles) to accommodate the lack of vertical scaling in the tests we give.   We’ve talked about implementing adequate growth in year 2, and simulating it in year 1, to give the field time to learn what it is and how it works before they are evaluated on it.  But make no mistake – SGP does not lack standards of growth.  It simply expresses them in a normative terms.



Media Contact: 

Alissa Muller, SBE Communications Manager, (360) 725-6501