Update README.md

add balanced accuracy for SelfCheck-BERTScore

demo/experiments/balanced_accuracy/README.md

@@ -3,11 +3,13 @@ Balanced Accuracy
 
 - Sentence-level balanced accuracy for the Wikibio dataset
 - For these results, the threshold is set to be 0.5
+- For SelfCheckGPT with BERTScore, set `rescale_with_baseline=True` to ensure that the scores are calibrated in [0.0, 1.0] 
 - As the metric is balanced accuracy, NonFact and Factual scenarios yield the same results
 
 | Method               |  NonFact   |  NonFact*  |
 |----------------------|:------------------:|:------------------:|
 | Random Guessing      |        50.00       |        50.00       |
+| SelfCheck-BERTScore  |        59.31       |        63.42       |
 | SelfCheck-QA         |        62.87       |        60.08       |
 | SelfCheck-NLI        |        70.55       |        62.15       |
 | SelfCheck-Prompt (gpt-3.5-turbo) |      76.69     |     65.93      |