What is the Nevada Growth Model?
The Nevada Growth Model is both:
· A statistical model to calculate each student’s progress on state assessments.
· A tool for displaying student, school, and district results to educators and to the public.
What is the purpose of the Growth Model?
The purpose of the Nevada Growth Model is to provide a new way to track progress in student achievement- both growth of individual students and growth of groups of students.
What does the Nevada Growth Model tell us?
The Nevada Growth Model shows us:
· How individual students (and groups of students) progress from year to year toward state standards. Each student’s progress is compared to the progress of other students in the state with a similar score history on CSAP in that subject area.
· The observed growth among different groups of students at the state, district, and school level.
· The level of growth that we need to observe in order to say that students were, on average, on track to catch up or keep up (Adequate Growth)
· Schools and districts that produce the highest rates of growth in academic achievement. These schools or districts may not be ones with the highest test scores every year - growth level is completely independent of achievement level for individual students.
Why did Nevada adopt “Growth Model” to measure student progress?
Nevada has provided students, families, educators, and the general public with information about student, school and district performance based on the Nevada Criterion (CRT) reference test, annually since 2003.This information has been invaluable in helping schools and districts engage in program evaluation activities understanding, for example, how well district instruction and curriculum are aligned with the state’s curriculum frameworks, or how well a particular subgroup of students is performing by school, district, and across the state.
Until now, however, we have been unable to answer the question, “How much academic progress did a student or group of students make in one year, as measured by the CRT’s, in relation to their academic peers?” With the development of the growth model, it is now possible to answer this question. This method of examining student growth will help districts and schools to look into why results differ for certain groups of students and support discovery of which approaches are working best to help more students to higher levels of academic performance.
What is student growth?
Growth is change over time.
The U.S. Department of Education defines student growth as the change in student achievement for an individual student between two or more points in time.
Student growth is the rate of learning of a single student.
What is a growth model?
For K-12 education, the phrase “growth model” describes a method of measuring individual student progress on statewide assessments (tests) by tracking the scores of the same students from one year to the next.
Traditional student assessment reports tell about a student’s progress, whereas growth reports tell how much a student has grown from year to year.
What is a scale score?
A scale score is an examinee’s calculated total score on a test. The Nevada Criterion-Referenced Tests (CRT) scales used by Nevada go from 100-500 points. Note that this is different from a “raw score”, which would be a tally of the total number of questions on a test that an examinee answered correctly. The use of scale scores makes it easier to interpret test results in many cases.
Are all students with student growth percentiles included in the bubble for a district/school/other group?
Not exactly, in order to receive a student growth percentile in a CRT content area, a student needs to have valid scores in that content area from two consecutive years, following a normal grade progression. Every student that matches these criteria will have a student growth percentile calculated, and educators who have access to the data can get those individual growth scores even when they are not represented in a bubble.
The school growth level (a bubble’s horizontal position in the plots) for the whole school or any subgroup of a school includes only those students who were enrolled in that school on the count date of that academic year.
The district growth level (a bubble’s horizontal position in the plots) for the whole district or any subgroup of a district only for those students who were enrolled in a school in that district by the count date of that academic year, or if they were continuously enrolled in that district for two consecutive years regardless of their count date status.
Finally, bubbles are only displayed for groups that have 25 or more students with growth scores.
Why are some bubbles bigger than others?
The larger a school in terms of total enrollment, the larger its bubble is. Note that total enrollment can be quite different from the number of students that the CRT, or the number of students that have growth percentiles, or the number of students included in school or district growth calculations.
Some bubbles look really small-how many kids are in those bubbles?
Public data is always protected by only displaying bubbles that contain 25 or more individuals’ growth scores. For this reason, you will never see a bubble that represents fewer than 25 individuals. This practice protects the privacy of those individuals so that it would be impossible to know who exactly they were through some process of elimination.
How do I find scores for different content area or year?
The square labels in the upper right-hand corner of the application window toggle between math and reading. The year pull-down menu below that enables you to switch years. The year shown is the second calendar year of a given academic, year, so 2010 refers to the 2009-2010academic year.
What is the state proficiency line and how do I interpret it?
The state proficiency line is a way of understanding how a particular school’s achievement level compares to that of all other schools in the state at that level. A school whose bubbles appear below the state proficiency line has a lower percentage of students scoring Proficient and Advanced than the average of all schools in the state.
How do I get demographic information about a school or district?
When placing mouse or curser over a bubble, a pop-up window appears giving you some growth details. In the upper right-hand corner of this “data tip” window is a blue circle with an “I” in it. Click on it and you will get another data tip with a lot more details about the students whose data are represented in that bubble.
I see bubbles that represent schools. How do I show bubbles that represent districts?
Mouse over any school bubble and choose View this School>Up to Districts. All the districts currently loaded in your display will be shown.
I chose a district, but some of the schools in the district are grayed out in the right-hand navigation list. Why can’t I see their data?
Public data are always protected by only showing bubbles that contain 25 or more individuals’ growth scores. For that reason, you will never see a bubble that represents fewer than 25 individuals. This practice protects the privacy of those individuals so that it would be impossible to know who exactly they were through some process of elimination.
If I check two different boxes in the Explore menu, does it find schools that match both of those criteria?
No. In this case the application displays schools that match either of those criteria. In some cases both the criteria might be matched, but the only way to find out which ones that might be is by toggling the check boxes one at a time and keeping track of your targets.
I would like to share what I just saw with another person by e-mail. How do I point them to the data I am looking at?
In the Nevada Model School View, you can simply copy the web address (URL) in your browser window and paste it into an e-mail address-anyone clicking on it will see the same selections that you have made.
Sometimes the URL can get very long-just grab the short URL from the text box in the Share window instead, and paste that into your e-mail.
How can I label the bubbles in my view?
In the current version of the Nevada Growth Model, you can apply up to ten labels so that you can track those bubbles more easily. Just hit the ‘Enable Bubble Labels’ button. You can move the labels around so that they appear just right for you set of bubbles.
How can I remove schools from the display list?
You can only filter out a whole school level such as Middle Schools. You cannot remove one or more particular schools.
The link provided does not take me to a school’s website; it takes me to the district’s website instead.
If a school does not supply Nevada Department of Education (NDE) with an up-to-date website to link to, NDE substitutes the district’s website instead. This generally enables users to easily navigate to a school’s website, if there is one.
I cannot mouse over a bubble that I want to investigate because there are too many other bubbles around it.
If you click on the name of the school in the alphabetical list on the right, it is easier to see exactly where the bubble is. You can further reduce the clutter by removing schools from the display that are a level you don’t need at the moment, such as Middle Schools. If you double click on the name of the school in the alphabetical list on the right, that school will be broken out by grades. If you are interested in a different break out you can choose one from the pull-down menu in the upper left-hand corner of the application window.
How does Nevada’s Growth Model work?
The Nevada Growth Model takes a student’s score in “year 1” and finds all other student's in the state who got exactly that same score, say in math. Then we look at all of the “year 2” math scores for the same group of students and see how the student in which we are interested scored compared to the other students in the group. Growth is reported in percentiles.
What test data is being used to calculate growth?
Every student with both spring 2010 and spring 2011 scores will have a growth calculation.
Are we comparing spring to spring data at this time?
Yes. The release is based on spring tests.
Will growth model data be a part of AYP?
Not this year. Nevada’s growth model has not yet been approved for AYP use.
Are the student peer groups pulled from the state or the district?
State level data for the grade level and content area is used to construct the academic peer groups.
What questions can a growth model help answer?
The growth model allows districts and school to more easily identify problems, or potentially struggling, programs and practices-and therefore to look deeper into what may or may n not be working.
A growth model can help answer such questions as:
A. How much academic progress did an individual or group of students make in one or more year?
B. How does an individual student’s growth on the Nevada CRT test compare?
How does Nevada measure student growth?
Nevada measures growth for an individual student by comparing the change in his or her CRT achievement from one year to a subsequent year to that of all other students in the state who had similar historical CRT results (the student’s “academic peers”). This change in achievement is reported as a student growth percentile (Abbreviated SGP) and indicates how high or low that student’s growth was as compared to that of his/her academic peers.
For a school or district, the growth percentiles for all students are aggregated to create a median student growth percentile for the school or district. The median student growth percentile is a representation of “typical” growth for students in the school or district.
Why didn’t Nevada report growth previously?
Nevada needed three things to be able to measure and report student growth:
· A statewide individual student tracking system;
· A statewide assessments administered in consecutive grades in the same subjects.
· A technically sound and understandable method for measuring growth that was compatible with the assessment system.
The state had all three of these components in place as of 2010.
For which grades and subjects does Nevada report growth?
Nevada reports growth for reading and mathematics for grades 4 through 8.
The Nevada growth Model uses students’ historical CRT results to calculate growth percentiles, as such, no results will be available for grade 3 ( the first grade of CRT Testing) or for science (because science is testes only in grades 5, 8, and high school.)
Will all students be included in growth reports?
No. As noted above, students in grades 4 through 8 who have two or more consecutive years of CRT results will be included in growth reporting. School-level growth reports give users the option of including students who were tested in the same school in which they were enrolled at the beginning count day of the school year, any students who were enrolled after count day.
Any student who took the Nevada Alternate Assessment in the two most recent CRT administrations will not be included in growth reports.
Is growth a better measure of student performance than CRT or AYP?
No. It simply answers a different question. If you want to know how well a student performed on the standards for mathematics or reading by the end of the 6th grade, the CRT scaled score and performance level are the best indicators. If you want to know whether a school is on target for having all of its students Proficient by 2014, AYP reports are the right measure. I you are trying to determine how much a student’s performance has changed from 2010 to 2011 relative to the student’s academic peers, the growth model is the best indicator. A more complete understanding of performance can be obtained by using all three measures.
Will growth data be used for accountability (AYP) determinations?
Not initially. As of this printing, the department is using growth data only as a supplement to the other CRT results we already provide. The department may decide to submit a request to the U.S. Department of Education to use growth in accountability decisions at a later date.
Will the state provide growth data for High Schools?
Yes. The fall of 2012 will be the first opportunity to calculate growth for high school students. Therefore, we must use grade 7 and /or tests as the prior year.
What is a student growth percentile?
A student growth percentile (abbreviated SGP) measures if a student’s performance has improved from one year to the next relative to his or her academic peers: other students statewide with similar CRT test scores in prior years. The calculation answers the questions, “Among other students with similar CRT test score histories in previous years, what is the range of scores attained this year?” The model then uses the answer to determine whether a student grew at a faster or slower rate than the students’ peers, or at a similar rate.
The statistic is interpreted as follows: if John Smith, currently a grade 5 students, has a student growth percentile of 65 in reading, which means that John improved more between grades 4 and 5 than 65 percent of students statewide with similar historical pattern of CRT test scores. Similarly, if John had a student growth percentile of 44 mathematics, it means that he improved more than only 44 percent of students statewide with a similar CRT test score history.
Can students who perform at the top range of the Exceed Standards level show growth?
Yes. One of the department’s criteria for selecting a model was that it had to measure growth even at the top (and bottom) of the CRT performance scale. This way, all students would have the opportunity to exhibit growth. The model accounts for this by measuring each child’s growth relative to his or her academic peers.
What does the median student growth percentile at my school represent?
The median student growth percentile is the midpoint of student growth percentiles in the school half of the students had student growth percentiles higher than the median; half had lower. This is a good way of describing the typical growth of students in the school. It is not appropriate to use the average (“mean”) when comparing percentiles.
Can the student growth percentile be interpreted the same way regardless of grade?
Yes. A Student with a student growth percentile of 60 improved more than 60 percent of his academic peers relative to their performance the prior year, whether that student is enrolled in grade 4, 5, 6, 7, 8.
Can the student growth percentile be interpreted the same way regardless of the test’s subject matter?
Yes. A student with a student growth percentile of 60 in Reading improved more than 60 percent of his academic peers in Reading relative to the prior year. A student with a student growth percentile of 60 in mathematics improved more than 60 percent of his academic peers in mathematics.
Can two students with different score histories have the same student growth percentiles?
Yes. Each student’s growth is compared only to that of others with a similar CRT test score history. The performance of Student A or Student B is compared to that of their academic peers statewide with similar trajectories because Student A and Student B have different score histories, Student A is not compared to Student B.
Can two different students with the same CRT Scaled score test histories have different student growth percentiles?
Yes. This can happen for at least two reasons. First, the growth calculation takes into account a students’ entire CRT test score history, not just that of the previous year. Therefore, two students could have the same scaled scores in 2010 but different scaled scores in 2009 or earlier and therefore receive the same student growth percentile. Second, the student growth percentile metric is calculated from a transformation of the raw scores that underlie the scaled scores, not the scaled scores themselves. As many as five different raw scores can translate into the same scaled score, especially for students at the time Warning/Failing and advanced performance levels. Students with the same scaled score history may not have the same raw scores and therefore would not receive the same student growth percentiles.
If my school made AYP, does that mean my students are growing faster than their academic peers?
No. AYP determinations are based on absolute achievement and not related to growth measures. Therefore, it is possible for schools to make AYP and have low growth, if most of the school’s students have achieved at the proficient level but their performance grows more slowly than that of their academic peers. Likewise, it is possible for a school to have most of its students growing at high rates and still not make AYP.