# How accurate and reliable are MAP Growth linking studies?

Document created by Community User on Feb 14, 2017Last modified by Community User on Jun 6, 2017
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Question
How accurately does MAP Growth predict how my students will perform on our state summative assessment?

MAP Growth is a strong predictor of how students will perform on state summative assessments. There is a high correlation between MAP Growth scores and state scores, and there is a high consistent rate of classification.

Correlation:
Correlation refers to how closely two data points (like a MAP Growth test score and a state summative test score) are related. In MAP Growth linking studies, the strength of the correlation is given by the correlation coefficient. The correlation coefficient is expressed as a number between -1 and 1, and measures the strength of the linear relationship between two scores. Positive values indicate positive correlation (for example, when one score goes up, the other score goes up). Negative values indicate negative correlation (for example, when one score goes up, the other goes down). A value of 0 indicates no correlation. The closer the value is to 1 or -1, the stronger the correlation.

You can find the correlation coefficient for your specific state in the second paragraph of the appendix in your state's linking study (typically page 24). As an example, the correlation coefficients between SC READY (the South Carolina state summative assessment) and MAP Growth are above 0.84 for all grades and subjects, indicating a strong positive relationship between MAP Growth and SC READY scores.

Consistency rate of classification:
Consistency rate of classification shows how accurately the MAP Growth score can predict a student's proficiency status in the state summative assessment. It is expressed as a number between 0 and 1. The closer the value is to 1, the more consistently the MAP Growth score can predict a student's proficiency status.

You can find the consistency rate of classification, as well as rate of false positives and false negatives, in the Consistency Rate of Classification section of the linking study, typically beginning on page 8. As an example, the consistency rate for the South Carolina SC READY assessment is above 84% for all grades and subjects.

Article Number
3289