## What is a good Rmsep?

RMSEP/standard deviation is called Relative Root Mean Squared Error (RRMSEP) 1/RRMSEP is also a metric. A value greater than 2 is considered to be a good.

**What does Rmsecv mean?**

Root Mean Square Error of Cross Validation

Root Mean Square Error of Cross Validation (RMSECV)

**What is Rmsee?**

The Root Mean Squared Error of Estimation (RMSEE) is calculated as the root squared distance between the real Y variable – the estimated Y variable. This means that its value depends on the original Y variable scale.

### How is cross-validation calculated in RMSE?

The RMSEj of the instance j of the cross-validation is calculated as √∑i(yij−ˆyij)2Nj where ˆyij is the estimation of yij and Nj is the number of observations of CV instance j.

**How do you calculate leave one out cross-validation mean squared error?**

In Leave-one-out cross validation (LOOCV) method, for each observation in our sample, say the i-th one, we first fit the same model keeping aside the i-th observation and then calculate the mean squared error for the i-th observation. Finally we take the average of these individual mean squared errors.

**Do you want a high or low RMSE?**

Lower values of RMSE indicate better fit. RMSE is a good measure of how accurately the model predicts the response.

## How do you read RMSE values?

How to Interpret Root Mean Square Error (RMSE)

- Σ is a fancy symbol that means “sum”
- Pi is the predicted value for the ith observation in the dataset.
- Oi is the observed value for the ith observation in the dataset.
- n is the sample size.

**What r2 value is significant?**

12 or below indicate low, between . 13 to . 25 values indicate medium, . 26 or above and above values indicate high effect size.

**Is a high R-squared value good?**

In general, the higher the R-squared, the better the model fits your data.

### What is rmsep in Nir?

RMSEP stands for Root Mean Square Error of Prediction RMSEP or SEP is the simplest and most efficient measure of the uncertainty in NIR predictions. This value is a measure of the average uncertainty that can be expected when predicting new samples.

**What is the difference between MSEP and rmsep?**

MSEP/RMSEP: prediction error, i.e. measured on real cases and compared to reference values obtained for these. RMSEP can measure e.g. how performance deteriorates over time (e.g. due to instrument drift), but only if the validation experiments have a design that allows to measure these influences.

**How important is rmsep in prediction?**

R2 in prediction is indeed not important and NO, there is no “if RMSEP is low, then R2 should be high” in PLS prediction. The point is that the new fields have lower variability compared to the big dataset that was used for model building using CV. RPIQ for prediction is high, so there is no problem with that.

## Why is rmsep lower than rmsecv for PLSR?

I calibrated and cross-validated a PLSR model on the 70% of the data and then used the built model to predict the remaining 30% of the samples. The RMSEP, in this case, is lower than RMSECV. I think this can happen when you calibrate and cross-validate a model on a very diverse samples set and then predict a much less diverse samples set.