diff --git a/TODO.txt b/TODO.txt
index 607fff6..d263387 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -1,4 +1,5 @@
 - [TODO] adapt BayesianCC to WithConfidence interface
+- [TODO] document confidence
 - [TODO] Test the return_type="index" in protocols and finish the "distributin_samples.py" example
 - [TODO] Add EDy (an implementation is available at quantificationlib)
 - [TODO] add ensemble methods SC-MQ, MC-SQ, MC-MQ
diff --git a/quapy/error.py b/quapy/error.py
index 1b2f745..201ab8f 100644
--- a/quapy/error.py
+++ b/quapy/error.py
@@ -363,8 +363,8 @@ def __check_eps(eps=None):
 
 
 CLASSIFICATION_ERROR = {f1e, acce}
-QUANTIFICATION_ERROR = {mae, mnae, mrae, mnrae, mse, mkld, mnkld, mean_bias_binary}
-QUANTIFICATION_ERROR_SINGLE = {ae, nae, rae, nrae, se, kld, nkld, bias_binary}
+QUANTIFICATION_ERROR = {mae, mnae, mrae, mnrae, mse, mkld, mnkld}
+QUANTIFICATION_ERROR_SINGLE = {ae, nae, rae, nrae, se, kld, nkld}
 QUANTIFICATION_ERROR_SMOOTH = {kld, nkld, rae, nrae, mkld, mnkld, mrae}
 CLASSIFICATION_ERROR_NAMES = {func.__name__ for func in CLASSIFICATION_ERROR}
 QUANTIFICATION_ERROR_NAMES = {func.__name__ for func in QUANTIFICATION_ERROR}