The Largest One-Year Gain in the State

Andover Elementary School's 2025-26 results in English and in math each rose by more than any other town district's in Connecticut. The gains are real, they survive the adjustment that usually explains these things away, and they are one year in a school of about a hundred tested students. Here is the whole picture, including the parts that complicate it.

This is the version first published on September 18, 2026, kept unchanged. Connecticut released its accountability data at the end of October, and the current edition has been updated with it. Where the two differ, the current edition is right. This page is here so the original wording stays on the record.

The Rivereast News Bulletin reported the results on September 18, under the headline "Andover Elementary Celebrates Increase in Test Scores." The article followed Principal Taylor Parker's presentation to the Board of Education on September 9, and she did not undersell it:

I'm so excited. Thank you for letting me share in celebrations, because we definitely have a lot to celebrate.

— Taylor Parker, AES principal, Board of Education meeting, Sept. 9, 2026

Every figure in that article checks out. We compared each one against the state's own published data — the proficiency rates, the growth figures, the statewide averages and the index scores — and they match. What follows is not a correction. It is the context a single school's announcement is not in a position to supply: where those numbers put Andover among Connecticut's 164 town districts, which of them carry the most weight, and which should be held lightly.

The underlying numbers are public, and they are worth setting out in full, because a result this good invites two opposite mistakes. One is to wave it away as noise or as a demographic accident. The other is to treat a single year as proof of something permanent. Neither is right, and the data is detailed enough to say so precisely.

Everything below comes from the Connecticut State Department of Education's public EdSight system, released in late August. Every figure is also published here as a spreadsheet — the full workbook carries the district-by-district data behind this page, and names the sheet each figure can be checked against. (The 2025-26 growth figures below were published after it was last built, and will be added on its next refresh.)

What the state publishes

Connecticut scores every district on a 0-100 performance index, separately for each subject. Andover's rose 6.1 points in English and 6.8 in math.

The performance index is the state's summary of how students did on the annual assessments — Smarter Balanced in English and math, the NGSS science test — placed on a common 0-100 scale so districts can be compared. The state publishes it subject by subject; it does not publish a single combined figure. Connecticut's stated target is 75 in each subject. A year ago Andover was below it in both English and math. It is now above it in both.

English language arts performance index for every Connecticut town district, 2024-25. Andover is at 73.1, the state at 64.7.

English language arts, 2025-26, on the same scale. Andover has moved to 79.2 while the state has barely moved, at 65.0.

Mathematics performance index for every Connecticut town district, 2024-25. Andover is at 68.7, the state at 61.1.

Mathematics, 2025-26, on the same scale. Andover has moved to 75.5, the state to 61.7.

Each pair is drawn on one scale, so the movement between years is directly comparable. Across the state, the English index went from 64.7 to 65.0 and the math index from 61.1 to 61.7.

+6.1  Andover's one-year change in English language arts, from 73.1 to 79.2
+6.8  Andover's one-year change in mathematics, from 68.7 to 75.5
1st of 164  where each of those gains ranks among town districts
+0.1 and +0.4  the median change across town districts, English and math

Neither is a close call. In English, the next largest gain was 4.5 points; in math, 5.6. Six districts gained three points or more in English and ten in math. Just over half of all districts improved at all: 55 percent in English, 59 percent in math.

Change in the English language arts index between 2024-25 and 2025-26 for all 164 Connecticut town districts, ranked. Andover's +6.1 is the largest gain.

Change in the mathematics index between 2024-25 and 2025-26 for all 164 Connecticut town districts, ranked. Andover's +6.8 is the largest gain.

Among the state's town districts, Andover moved from tied for 55th to 15th in English, and from tied for 67th to 23rd in math.

In Andover's own record, neither subject has moved this far in a single year. The previous largest one-year gain was 3.8 points in English, between 2021-22 and 2022-23, and 1.1 points in math.

It is worth being exact about one thing the charts do not say. These are Andover's largest one-year gains, and its best results since 2018-19 — but not its best ever. Andover scored 81.0 in English and 76.5 in math in 2018-19, before the pandemic. What 2025-26 represents is most of the way back to where Andover was before COVID.

The third subject, and the combined figure

Science fell. How you combine the three subjects changes the ranking, so here it is every way.

−3.3  science, from 76.5 to 73.2, now just below the state's target of 75

Science is tested only in grades 5, 8 and 11, so in Andover it rests on roughly two dozen students in a single grade — small enough that a few children moving a band or two will swing it several points. It is the least stable of the three figures in either direction, and it should not carry much weight on its own. It is included here because leaving it out would be the kind of selective reporting this series exists to correct.

Because EdSight does not publish a single figure across subjects, any combined number is a choice someone has made. The one used in the rest of this page is ours: the three subject indices weighted by the number of students who sat each test. That keeps science, which only three grades take, from counting as a full third of the result. By that measure Andover rose from 71.5 to 76.9, also the largest gain in the state.

Weight the three subjects equally instead, and the answer changes. Andover's combined gain becomes 3.2 points, and it ranks sixth among the 156 districts reporting all three — because the one subject that fell is given the same weight as the two that rose. That is a legitimate way to look at it, and it is why the headline claim on this page rests on the subjects themselves: first in the state in English, and first in the state in math.

Change in the combined performance index between 2024-25 and 2025-26, weighted by students tested, for all 164 town districts. Andover's +5.5 ranks first; weighted equally it would rank sixth.

The test that usually explains these things away

District test scores mostly measure which students a district serves. Andover's gain survives that adjustment.

This is the single most important thing to understand about school test data, and it is the reason a result like Andover's deserves scrutiny before celebration.

Across Connecticut, the strongest predictor of a district's results is not its spending, its size, or its leadership. It is the share of its students who are classified as high needs — eligible for free or reduced-price meals, an English learner, or a student with a disability. On the combined index, that one variable explains about three quarters of the difference between districts.

Combined performance index against high-needs share for every Connecticut town district, 2024-25. The relationship is strongly negative, with r equal to minus 0.873.

The same chart for 2025-26. The relationship is essentially unchanged, with r equal to minus 0.878, and Andover has moved up relative to the line.

The relationship is almost exactly as strong in the new year as the old one: r = −0.873 in 2024-25, −0.878 in 2025-26. Every ten percentage points of additional high-needs enrollment is associated with roughly four and a half fewer index points.

So the fair question is not "did Andover's score go up" but "did it go up by more than the change in its students would predict." Andover's high-needs share did fall, from 38.3 percent to 35.8 percent. That accounts for part of the gain — but only part.

+5.5  Andover's raw gain on the combined index
+4.1  the gain that remains after adjusting for the change in student need
+1.0 → +5.1  Andover's position relative to what its demographics predict

Measured against the statewide pattern, Andover went from performing about as expected to performing five points better than expected — the district's strongest showing on that measure since 2018-19.

On the combined index, Andover's rank among the state's town districts moved from 61st of 165 to 22nd of 164. Within its own comparison group of small districts without a high school, from 22nd of 45 to 9th of 44.

What one year can and cannot tell you

About a hundred students sit these tests. That cuts both ways.

Andover Elementary tested 109 students in 2025-26. In a district that size, each child is worth roughly a full percentage point of any subgroup figure, and year-to-year results are genuinely volatile: on the combined index, districts testing fewer than 200 students swing about two and a half times as much from year to year as districts testing 600 or more.

That volatility is exactly why Andover's result is notable rather than routine — its gains are the largest in the state in both English and math, including against the small districts where large swings are most common. But it is also why a single year should not be read as a trend. The honest statement is that Andover has had an excellent year, on top of a long record of performing at or above what its demographics predict, and that one more year of data will say much more than this one does.

The fairer measure, and what is still to come

Growth is the measure that best isolates what a school contributes. On it, Andover's year is more remarkable than the headline suggests.

The performance index measures where students are. It does not measure how far they moved, and because it tracks so closely with student need, it is a limited tool for judging a school's own contribution.

Connecticut publishes a better measure: academic growth, which matches each individual student to their own prior-year score and asks what share of their personal growth target they achieved. It is far less determined by demographics — student need explains about a quarter of the variation in growth, against three quarters for the combined index — which makes it the fairer measure of a district's work.

Connecticut reports growth two ways. The growth rate is the share of students who met their target — the figures Parker gave the board. The average percentage of target achieved counts partial progress too, and it is the version the state uses in its accountability system. On that second measure:

85.0  Andover, 2025-26, averaged across English and math
60.1  Connecticut, 2025-26
69.5 and 61.4  the same two figures a year earlier

Andover went from eight points above the state to twenty-five, while the state itself edged down.

This is arguably the more impressive half of Andover's year, and it is the half least explained by who its students are.

One caution on timing. These growth figures are published now, with the assessment results. What arrives around November is the Next Generation Accountability release, which packages growth as one indicator among twelve and adds the rest: chronic absenteeism, physical fitness, and, for districts that have them, graduation and college-and-career measures. That is the release this page will return to.

The rest of the picture, 2024-25

The six charts below are the full comparison set for the most recent year in which every measure exists.

Two of them repeat measures from above, at that year, so the set can be read on its own. Where a chart shows performance across all three subjects, it uses the combined index described above.

Combined performance index for every Connecticut town district, 2024-25.

Academic growth for every Connecticut town district, 2024-25. Andover is at 69.5, the state at 61.4.

Combined performance index against total per-pupil spending, 2024-25. The relationship is weak, with r equal to plus 0.268.

Academic growth against total per-pupil spending, 2024-25. The relationship is weak, with r equal to plus 0.287.

Combined performance index against high-needs share, 2024-25.

Academic growth against high-needs share, 2024-25. The relationship is much weaker than for the combined index.

Two things stand out in that set, and both are worth stating plainly because they cut against arguments made in every direction locally.

The first is that per-pupil spending barely relates to results at all. Across the state's town districts, spending explains something like seven percent of the difference in the combined index and eight percent in growth — and once student need and grade span are accounted for, no statistically detectable amount. That is not evidence that money does not matter. It is evidence that what varies between Connecticut towns is mostly district size and geography, not educational effort, and that test scores cannot settle a budget argument in either direction.

The second is that growth tracks student need far less closely than the combined index does. That is the case for paying attention to the November release rather than this one.

What the school said, and what the numbers add

The article's figures are accurate. Three of its themes are worth extending.

On growth. Parker drew the distinction that matters most in this data, and drew it correctly:

Every student gets a target, whether you score a one or a four. So even students performing above grade level have a target score.

— Taylor Parker, Board of Education meeting, Sept. 9, 2026

That is exactly why growth is the fairer measure. Achievement scores largely track which students a district serves; growth asks how far each student moved from their own starting point, and is far less determined by demographics. The figures she gave the board — 68.7 percent of students meeting their ELA target, 67.5 percent in math, against 44.4 and 41.1 a year earlier — are the state's published growth rates, and they are correct.

On the achievement gap. The article reports that the gap between high-needs students and their classmates narrowed in both subjects, from 20.7 points to 14.5.

We want all students growing.

— Taylor Parker, Board of Education meeting, Sept. 9, 2026

This is the one figure on which we can offer no independent check. Andover's high-needs subgroup is small enough that the state suppresses its results publicly to protect student confidentiality, so the underlying numbers are not in EdSight. The claim comes from the district's own data, and should be read as such — not because there is reason to doubt it, but because it cannot be verified the way everything else here can.

On not over-reading one year. The article closes on a note of caution that this page would make anyway, and it is to the school's credit that it came from the school:

It is not a one-shot deal. We can't just say we had one good year.

— Taylor Parker, Board of Education meeting, Sept. 9, 2026

About 110 students sit these tests. That is small enough that a strong cohort moves the whole district figure, in either direction. The case for taking this year seriously is not the size of the jump on its own; it is that the jump survives adjustment for student need, that it holds in both subjects independently, and that it sits on a decade in which Andover has almost always performed at or above what its demographics predict.

More to come in November

Connecticut's Next Generation Accountability release, which sets this year's growth
alongside attendance, fitness and the rest of its twelve indicators, is published
around November. A fuller district-by-district report will follow here when it lands.

Sources

Compiled by Scott Sauyet, Andover, from Connecticut State Department of Education public data. Posted at andoverct.info/the-facts. This page is part of an ongoing series; new editions appear at the same URL as the local conversation evolves. Earlier editions remain accessible at their permanent URLs (use the menu to navigate).