> ## Documentation Index
> Fetch the complete documentation index at: https://docs.learningcommons.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Subject Matter Knowledge

> Reference documentation for the Subject Matter Knowledge literacy evaluator.

export const EarlyAccessCallout = ({children}) => <div className="eyebrow-callout not-prose rounded-xl border border-gray-200/80 p-5 dark:border-white/10" style={{
  marginBottom: "1rem",
  borderRadius: "4px"
}}>
    <div className="mb-3">
      <Badge color="green" size="md" icon="flask">
        Early access
      </Badge>
    </div>
    <div className="callout-body text-[15px] leading-relaxed text-gray-700 dark:text-gray-300">{children}</div>
    <style>{`.callout-body a { text-decoration: underline; text-decoration-color: #178251; }`}</style>
  </div>;

[Evaluator last updated March 13, 2025.](#evaluator-release-history)

<EarlyAccessCallout>
  This functionality is actively evolving. Changes may occur as we expand
  capabilities and improve accuracy and reliability. Email
  [support@learningcommons.org](mailto:support@learningcommons.org) ↗ with your
  feedback or issues.
</EarlyAccessCallout>

## Overview

The Subject Matter Knowledge evaluator assesses the subject-matter complexity of reading passages:

* Evaluates how much prior knowledge a text relies on
* Lists key concepts in the text
* Evaluates whether students have likely encountered these concepts before

## At a glance

|                      |                                                                                                                                                                                                             |
| :------------------- | :---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Input type**       | Informational text                                                                                                                                                                                          |
| **Supported grades** | 3-12                                                                                                                                                                                                        |
| **Rubric**           | [SAP](https://learnwithsap.org/) ↗'s [Qualitative Text Complexity Rubric for Informational Text](https://learnwithsap.b-cdn.net/app/uploads/2026/04/Qualitative-Text-Complexity-Rubric-Informational.pdf) ↗ |

The evaluator was built and validated using the model and temperature below (other configurations will produce different results and may have lower accuracy):

|                 |                        |
| :-------------- | :--------------------- |
| **Model used**  | gemini-3-flash-preview |
| **Temperature** | 0                      |

## Getting started

Follow the [Quickstart](/evaluators/getting-started/quickstart) to start using this evaluator:

| Access method             |                                                                                                                                                           |
| :------------------------ | :-------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Evaluators Playground** | [View in the Learning Commons Platform](https://platform.learningcommons.org/apps/evaluators/playground?utm_source=docs\&utm_medium=evaluators) ↗         |
| **SDK**                   | [TypeScript](https://github.com/learning-commons-org/evaluators/blob/main/sdks/typescript/src/evaluators/smk.ts?utm_source=docs\&utm_medium=evaluators) ↗ |
| **Python notebook**       | [View in GitHub](https://github.com/learning-commons-org/evaluators/blob/main/evals/smk_evaluator.ipynb?utm_source=docs\&utm_medium=evaluators) ↗         |
| **Prompts**               | [View in GitHub](https://github.com/learning-commons-org/evaluators/blob/main/evals/prompts/smk_prompts.py?utm_source=docs\&utm_medium=evaluators) ↗      |

## Inputs

| Input                  | Description                                             | Required |
| :--------------------- | :------------------------------------------------------ | :------- |
| **Target grade level** | Enables grade context evaluation                        | Yes      |
| **Text type**          | Informational text<br />Optimal length: 200-1,000 words | Yes      |

## Output

| Field                           | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| :------------------------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Complexity rating**           | <ul><li><strong>Slightly complex:</strong> Relies on everyday, practical knowledge; includes simple, concrete ideas</li><li><strong>Moderately complex:</strong> Relies on common practical knowledge and some discipline-specific content knowledge; includes a mix of simple and more complicated, abstract ideas</li><li><strong>Very complex:</strong> Relies on moderate levels of discipline-specific or theoretical knowledge; includes a mix of recognizable ideas and challenging abstract concepts</li><li><strong>Exceedingly complex:</strong> Relies on extensive levels of discipline-specific or theoretical knowledge; includes a range of challenging abstract concepts</li></ul> |
| **Reasoning**                   | Synthesized explanation of the decision                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
| **Identified topics**           | List of topics in the text                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| **Curriculum check**            | Classification of topics as general or specialized                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| **Assumptions and scaffolding** | Analysis of assumed prior knowledge vs. explained content                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| **Friction analysis**           | Analysis of the gap between concrete description and abstract meaning                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |

## Interpreting results

| Output                                              | How to use                                                                                                                                                                                                                                                                                                                                                                                                    |
| :-------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Complexity rating**                               | <ul><li><strong>Slightly complex:</strong> Confirm text relies on everyday knowledge students likely have</li><li><strong>Moderately complex:</strong> Plan light scaffolding for discipline-specific terms</li><li><strong>Very complex:</strong> Pre-teach key concepts before independent reading</li><li><strong>Exceedingly complex:</strong> Flag texts that assume extensive prior knowledge</li></ul> |
| **Identified topics + Assumptions and scaffolding** | Match text to what students have already encountered<br /><br />**Example**: Use identified topics, curriculum check, and friction analysis to decide what to pre-teach or explain in the text                                                                                                                                                                                                                |

## Accuracy and validation

<Note>
  This evaluator is provided as Early access. Comprehensive accuracy measures
  are not yet available. Validation testing is ongoing.
</Note>

We assessed performance against an expert-annotated dataset of texts from the [CLEAR Corpus](https://www.commonlit.org/blog/introducing-the-clear-corpus-an-open-dataset-to-advance-research-28ff8cfea84a/) ↗, rated by 3 experts, rather than traditional static benchmark metrics.

| Metric                        | **Description**                                                                                   | **Result**                                                 |
| :---------------------------- | :------------------------------------------------------------------------------------------------ | :--------------------------------------------------------- |
| **Complexity score accuracy** | How accurately the evaluator determines text complexity compared to the expert annotated dataset. | 87% based on agreement with 3 experts assessing \~30 texts |
| **Expert agreement rate**     | The agreement rate between the evaluator and experts on a sample of 10 evaluated texts.           | 100%                                                       |

For more information on our validation process, see [Accuracy](/evaluators/understanding-evaluators/core-concepts#interpreting-accuracy).

## Evaluator release history

| Date           | Changed       |
| -------------- | ------------- |
| March 13, 2026 | First release |