diff --git a/quacc/experiments/report.py b/quacc/experiments/report.py
index 9d38444..4f90745 100644
--- a/quacc/experiments/report.py
+++ b/quacc/experiments/report.py
@@ -6,9 +6,17 @@ from pathlib import Path
 import numpy as np
 import pandas as pd
 
+from quacc.error import nae
 from quacc.utils.commons import get_results_path, load_json_file, save_json_file
 
 
+def _get_shift(index: np.ndarray, train_prev: np.ndarray):
+    index = np.array([np.array(tp) for tp in index])
+    train_prevs = np.tile(train_prev, (index.shape[0], 1))
+    _shift = nae(index, train_prevs)
+    return np.around(_shift, decimals=2)
+
+
 class TestReport:
     def __init__(
         self,
@@ -141,7 +149,9 @@ class Report:
         stdevs = None if stdev is None else []
         for _method, _results in self.results.items():
             methods.append(_method)
-            _prevs = np.array([_r.test_prevs for _r in _results]).flatten()
+            _prevs = np.array(
+                [_r.test_prevs for _r in _results]
+            ).flatten()  # should not be flattened, check this
             _true_accs = np.array([_r.true_accs for _r in _results]).flatten()
             _estim_accs = np.array([_r.estim_accs for _r in _results]).flatten()
             _acc_errs = np.abs(_true_accs - _estim_accs)
@@ -157,5 +167,5 @@ class Report:
 
         return methods, prevs, acc_errs, stdevs
 
-    def shift_plot_data(self, dataset_name, method_names, acc_name):
+    def shift_plot_data(self):
         pass