Add docs

docs/source/index.rst

@@ -11,6 +11,7 @@ PyKEEN
    tutorial/byod
    tutorial/running_hpo
    tutorial/using_mlflow
+   tutorial/making_predictions
 
 .. toctree::
    :caption: Reference

docs/source/tutorial/making_predictions.rst

@@ -0,0 +1,39 @@
+Novel Link Prediction
+=====================
+After training, the interaction model (e.g., TransE, ConvE, RotatE) can assign a score to an arbitrary triple,
+whether it appeared during training, testing, or not. In PyKEEN, each is implemented such that the higher the score
+(or less negative the score), the more likely a triple is to be true.
+
+However, for most models, these scores do not have obvious statistical interpretations. This has two main consequences:
+
+1. The score for a triple from one model can not be compared to the score for that triple from another model
+2. There is no *a priori* minimum score for a triple to be labeled as true, so predictions must be given as
+   a prioritization by sorting a set of triples by their respective scores.
+
+After training a model, there are three high-level interfaces for making predictions:
+
+1. :func:`pykeen.models.Model.predict_tails` for a given head/relation pair
+2. :func:`pykeen.models.Model.predict_heads` for a given relation/tail pair
+3. :func:`pykeen.models.Model.predict_top_k_triples` for prioritizing links
+
+Scientifically, :func:`pykeen.models.Model.predict_top_k_triples` is the most interesting in a scenario where
+predictions could be tested and validated experimentally.
+
+.. code-block:: python
+
+    from pykeen.pipeline import pipeline
+    results = pipeline(dataset='Nations', model='RotatE')
+    model = results.model
+
+    # Predict tails
+    predicted_tails_df = model.predict_tails('brazil', 'intergovorgs')
+
+    # Predict heads
+    prediced_heads_df = model.predict_heads('conferences', 'brazil')
+
+Potential Caveats
+-----------------
+The model is trained on its ability to predict the appropriate tail for a given head/relation pair as well as its
+ability to predict the appropriate head for a given relation/tail pair. This means that while the model can
+technically predict relations between a given head/tail pair, it must be done with the caveat that it was not
+trained for this task.