Validating Growth Models
CCSSO
National Conference on Student Assessment
June 30, 2017
Validity and Validation
• In olden days, validity and validation were not
quite so complicated…
So let it be written.
So let it be done.
Why is your use of those test scores valid?
Validating the Growth Model
• … a process to ensure the growth model is valid
for its intended purpose
• What is the intended purpose?
– Of the accountability system?
• Of the growth model within the accountability system?
Why Growth?
• Someone needs to be able to explain the role
of growth within the accountability system?
– Not only to help determine whether the
appropriate growth model has been selected?
– But also to help with the evaluation of whether it is
serving its intended purpose as we validate the
accountability system
• Validating the Accountability System
– Braun (2008) Vicissitudes of the Validators
Validity of Accountability Systems
• Braun’s (2008) argument regarding the validity of
accountability systems:
1. An accountability system is imposed or implemented
with the intent that it will accomplish its desired goals
(e.g., increased student achievement).
2. The mechanism by which this will happen is called the
“theory-of-action”.
3. In validating an accountability system, the theory-of-
action plays the same role as does the construct in test
validation.
4. Thus, consequential validity is the ultimate criterion by
which we should judge an accountability system.
“Theory of Action”
• The accountability system
– Results in classifications
– Identifies schools for support and assistance
– Leads to actions
– Actions lead to improvement
• How does growth fit into the model?
– What are the intended uses and interpretations of
growth as part of the model?
– Is there a clear path for that information to lead to the
desired actions?
Back to Braun
4. consequential validity is the ultimate criterion
by which we should judge an accountability
system.
• Ultimate consequential validity question– Did the implementation of
the accountability system lead to the desired improvements in
performance?
• There are lots of dots to connect between the design of the
accountability system and improved student performance.
• As with everything else, trained professionals and fidelity of
implementation are critical.
• Isolating and evaluating the role and impact of the growth model
could be difficult?
• Is it necessary or useful to do so?
• How does validating the growth model fit into the overall plan for
validating the accountability system?
About this copy
Validating Growth Models — CCSSO, June 2017.
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