External validity indices

External validity indices are tools used to evaluate how well the results of a study or model apply to real-world situations beyond the original data set. They measure the consistency and accuracy of the model when tested on new, independent data. Essentially, these indices help determine whether findings are generalizable and reliable outside the initial context, ensuring that conclusions or predictions made by the model remain valid in different settings or populations. They are important for validating the broader usefulness of research findings.