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Main Impacts

Some schools span both middle and high grades. TKG Analytics scores those schools twice - once for the middle grades and once for the high grades - and then combines the two into a single main impact. This page explains which schools get one, why the two halves can look so different from each other, and how they are combined. For what each measure inside an impact means, see Impact Components.

Which Schools Get One

A split school or a non-traditional high school spans middle and high grades. On MAAP, each one produces three impacts:

  • a middle impact, covering its middle grades
  • a high impact, covering its high grades
  • a main impact, which combines the two

Only MAAP is split this way. A split school's other score types - MAAP-A / SCD, EL, and K-2 - each produce one impact for the whole school, exactly as they would anywhere else, so there is no main impact to look for on those.

A school that sits entirely within one grade band gets a single impact and no main impact. Districts and teachers never have one either - a main impact is a school-level result.

The Two Halves Are Graded Separately

This is the part that surprises people most often: the middle and high halves are graded as their own subgroups. Each computes its own components independently and is measured against its own cut scores.

That is why a split school's high-grade measures can read very differently from its middle-grade ones. They are not two views of the same calculation. They are two separate results for two separate groups of students, and neither is adjusted to match the other.

Why the Middle Half Is Converted

The two halves are not scored on the same scale. Middle grades are scored on the 700-point scale and high grades on the 1000-point scale, so the two numbers cannot simply be added or averaged - 350 out of 700 and 350 out of 1000 do not mean the same thing.

Before the halves are combined, the middle number is converted to its 1000-point equivalent using the conversion table published by the Mississippi Department of Education (MDE). The high number is already on the 1000-point scale and is used as it stands.

MDE issued a new conversion table beginning in 2026. Years before 2026 continue to use the table that was in force at the time, so a school's earlier results are unchanged. A main impact that looks different between 2025 and 2026 may reflect the new table as well as new scores.

How the Halves Are Weighted

The two halves are combined by student count, not averaged evenly. A school with a large middle half and a small high half sees its main impact track the middle half closely, and the reverse is equally true.

The student count comes from:

  • the school's month 8 enrollment for that year and score type, when one exists - see Month 8 Overview
  • otherwise, its active students in the relevant grade bands

This is why two schools with identical middle and high results can still land on different main scores: their enrollment split is different.

When a Main Impact Is Not a Blend

If neither half has a usable student count, there is nothing to weight. In that case the main impact scores its own components instead of combining its halves.

When that happens, the main number will not look like a blend of the middle and high numbers shown beside it. That is expected, not an error.

It takes both halves coming back with no students. A missing month 8 enrollment on its own is not enough, because the count falls back to the school's active students in those grade bands, so a school with students on file will normally still blend.

Where It Lives

Most pages show the main impact and leave the two halves out, so it is worth knowing which one carries which:

  • Impact Data, the per-score-type view for a school, is the only place that carries all three. The main impact sits on the MAAP tab alongside the school's other whole-school results, and the middle and high halves sit on their own NTHS MAAP tab.
  • All Impacts carries the main impact only. It puts every score type side by side, but for each one it shows the school's whole-school result rather than the two halves.
  • Report Cards carries the main impact only. The two halves are not on the report card.
  • Grade Impacts breaks results out by grade and has no middle, high, or main split at all.

Common Questions

  • Why does my main score not sit between my middle and high scores? It should, whenever both halves have students. If it does not, check that the school has students on file for both grade bands - only when neither half has a student count does the main impact score its own components rather than combining. Both halves are also converted to the same scale first, so comparing the main number directly against the raw 700-point middle number will not line up.
  • Why did my main score change for 2026? MDE issued a new conversion table beginning in 2026. Earlier years are unaffected.
  • My middle half is much lower than my high half. Is that a mistake? Not by itself. The halves are graded as separate subgroups against separate cut scores, so a real gap between them is normal.
  • Can I see the two halves separately? Yes, on the school's Impact Data view, under the NTHS MAAP tab. They are not on All Impacts or on the report card, both of which carry the main impact only.

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