Forecasting REST API

MetaMetrics Forecasting REST API uses a proprietary growth model to forecast student performance on an assessment that will be taken later in the school year. The Forecasting REST API uses recent results from interim/formative assessments published by its assessment partners to forecast performance. The forecasted performance is most commonly used* in relation to a state’s performance standards when both the interim/formative and the state assessments have been linked with the Lexile Framework® for Reading and/or the Quantile Framework® for Mathematics or reported directly using the Lexile® and/or Quantile® scales.

Two basic ideas underlie forecasting: first, that past performance can be used to predict future performance, and second, that any such predictions include some level of uncertainty that increases the further in the future that the predicted event will occur. Interim and formative assessments are used throughout the school year to evaluate a student’s current level of proficiency relative to the state curriculum and/or as a way to monitor progress or growth.

How the MetaMetrics Forecasting REST API Can Be Used

The MetaMetrics Forecasting REST API was designed to predict student performance on standardized assessments using the results of interim/formative assessments administered earlier in the school year.

For example, students are often administered standardized reading and mathematics exams upon returning to school in the fall in order to determine baseline proficiency or to place the students into instructional groups. When students receive a Lexile and/or Quantile measure based on their exam performance, the MetaMetrics Forecasting REST API can be used to estimate how much a student is likely to grow on the Lexile/Quantile scale(s) by a given point in time (e.g., January, March, May). These forecasted growth estimates can be used to set growth targets for students, and students can then be evaluated against those growth targets using the results of future standardized reading/mathematics exams.

In addition to providing growth projections, the MetaMetrics Forecasting REST API can also give educators a sense of how future student performances may relate to end-of-year summative assessment performance standards.

Updating Forecasted Growth and Performance Estimates

When students are administered interim/formative assessments at various times throughout the school year (e.g., fall, winter, spring), the Forecasting REST API can provide updated or refined growth projections and proficiency estimates by incorporating the most recent Lexile/Quantile measures.

For example, when a student completes a reading assessment in September, they receive a Lexile measure and a forecast of the Lexile measure that they will likely achieve if they retake the assessment in the spring (6-9 months later). If the student then retakes the reading assessment in January, the Lexile reading measure from the January administration can be used to update and refine the forecasted Lexile measure that the student is likely to achieve on that assessment in the spring. When forecasts are updated using new data points and made closer to the end of the year, the results are more accurate and better reflect student performance on end-of-year assessments.

Forecasting Performance and Comparing to State or Custom Standards

Performance standards are commonly used when reporting results from the administration of high-stakes mathematics and reading assessments to help describe whether students are performing below, on, or above level. Forecasting in relation to these standards makes the predictions even more useful.

MetaMetrics has linked the Lexile/Quantile scales with many state summative assessments (See States Performance Standards Database for more information). When this information is used in conjunction with the Forecasting REST API, forecasted student Lexile/Quantile measures can be compared with each performance level defined by the state.

Alternatively, if an assessment reports Lexile or Quantile measures across multiple testing events with custom-developed performance standards, this information can also be used with the Forecasting REST API to estimate the likelihood of a student achieving each performance level on a future administration.

Forecasting by Individual or Groups of Students

The MetaMetrics Forecasting REST API uses student assessment data (current student measures, uncertainty, and elapsed time between assessment administrations) to forecast or estimate the student’s performance on that assessment at a point in the future. The API supports two modes of forecasting: Individual and Group.
  • Individual mode returns an individual student’s predicted Lexile/Quantile measure on a future assessment and probabilities of scoring at each performance level.
  • Group mode returns student Lexile/Quantile measure predictions and performance level probabilities for each individual student as well as the mean prediction and probabilities for all students in a group.

See About Forecasting REST API for more information.

*The Forecasting REST API is also available for use with assessments that report Lexile® silent reading or Quantile® measures across multiple testing events and have custom-developed performance standards.