diff --git a/edustudio/model/KT/dkt_plus.py b/edustudio/model/KT/dkt_plus.py
index dd38419..57f22f0 100644
--- a/edustudio/model/KT/dkt_plus.py
+++ b/edustudio/model/KT/dkt_plus.py
@@ -8,7 +8,8 @@ class DKT_plus(DKT):
     default_cfg = {
         'lambda_r': 0.01,
         'lambda_w1': 0.003,
-        'lambda_w2': 3.0
+        'lambda_w2': 3.0,
+        'reg_all_KCs': True
     }
 
     def __init__(self, cfg):
@@ -31,7 +32,10 @@ def get_main_loss(self, **kwargs):
         loss_main = F.binary_cross_entropy(input=y_next, target=gt_next)
         loss_r = self.modeltpl_cfg['lambda_r'] * F.binary_cross_entropy(input=y_curr, target=gt_curr)
 
-        diff = (pred_shft - pred)[kwargs['mask_seq'][:, 1:] == 1]
+        if self.modeltpl_cfg['reg_all_KCs']:
+            diff = y[:, 1:] - y[:, :-1]
+        else:
+            diff = (pred_shft - pred)[kwargs['mask_seq'][:, 1:] == 1]
         loss_w1 = torch.norm(diff, 1) / len(diff)
         loss_w1 = self.modeltpl_cfg['lambda_w1'] * loss_w1 / self.n_item
         loss_w2 = torch.norm(diff, 2) / len(diff)