diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbDateVariable.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbDateVariable.java
index 4edd57448..ec8c2a3eb 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbDateVariable.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbDateVariable.java
@@ -35,6 +35,7 @@ public class WbDateVariable extends WbDateExpr {
         throw new SkipSchemaExpressionException();
     }
 
+    @JsonProperty("columnName")
     public String getColumnName() {
         return columnName;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemConstant.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemConstant.java
index abcbed58b..45c58c78e 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemConstant.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemConstant.java
@@ -1,6 +1,7 @@
 package org.openrefine.wikidata.schema;
 
-import org.openrefine.wikidata.schema.entityvalues.TermedItemIdValue;
+import org.openrefine.wikidata.schema.entityvalues.ReconItemIdValue;
+import org.openrefine.wikidata.schema.entityvalues.SuggestedItemIdValue;
 import org.wikidata.wdtk.datamodel.implementation.ItemIdValueImpl;
 import org.wikidata.wdtk.datamodel.interfaces.ItemIdValue;
 
@@ -25,16 +26,18 @@ public class WbItemConstant extends WbItemExpr {
 
     @Override
     public ItemIdValue evaluate(ExpressionContext ctxt) {
-        return new TermedItemIdValue(
+        return new SuggestedItemIdValue(
                 qid,
                 ctxt.getBaseIRI(),
                 label);
     }
 
+    @JsonProperty("qid")
     public String getQid() {
         return qid;
     }
 
+    @JsonProperty("label")
     public String getLabel() {
         return label;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemDocumentExpr.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemDocumentExpr.java
index ed79d9f72..6362af3b1 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemDocumentExpr.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemDocumentExpr.java
@@ -45,14 +45,17 @@ public class WbItemDocumentExpr extends JacksonJsonizable {
         return update;
     }
 
+    @JsonProperty("subject")
     public WbItemExpr getSubject() {
         return subject;
     }
 
+    @JsonProperty("nameDescs")
     public List<WbNameDescExpr> getNameDescs() {
         return nameDescs;
     }
 
+    @JsonProperty("statementGroups")
     public List<WbStatementGroupExpr> getStatementGroups() {
         return statementGroups;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemVariable.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemVariable.java
index ae50ec320..9eebde938 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemVariable.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbItemVariable.java
@@ -1,18 +1,14 @@
 package org.openrefine.wikidata.schema;
 
 
-import org.openrefine.wikidata.schema.entityvalues.NewEntityIdValue;
-import org.openrefine.wikidata.schema.entityvalues.TermedItemIdValue;
+import org.openrefine.wikidata.schema.entityvalues.ReconItemIdValue;
 import org.openrefine.wikidata.schema.exceptions.SkipSchemaExpressionException;
-import org.wikidata.wdtk.datamodel.helpers.Datamodel;
 import org.wikidata.wdtk.datamodel.interfaces.ItemIdValue;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 import com.google.refine.model.Cell;
-import com.google.refine.model.Recon;
-import com.google.refine.model.ReconCandidate;
 
 public class WbItemVariable extends WbItemExpr {
     /* An item that depends on a reconciled value in a column */
@@ -29,29 +25,12 @@ public class WbItemVariable extends WbItemExpr {
     public ItemIdValue evaluate(ExpressionContext ctxt) throws SkipSchemaExpressionException {
         Cell cell = ctxt.getCellByName(getColumnName());
         if (cell != null && cell.recon != null) {
-            Recon recon = cell.recon;
-            if (recon.judgment == Recon.Judgment.Matched && cell.recon.match != null) {
-                ReconCandidate match = cell.recon.match;
-                String label = match.name;
-                return new TermedItemIdValue(
-                        match.id,
-                        ctxt.getBaseIRI(),
-                        label);
-            } else if (recon.judgment == Recon.Judgment.New) {
-                int rowId = ctxt.getRowId();
-                int columnId = ctxt.getCellIndexByName(getColumnName());
-                String siteIRI = ctxt.getBaseIRI();
-                String label = cell.value.toString();
-                if (label.isEmpty()) {
-                    
-                }
-                return new NewEntityIdValue(
-                        rowId, columnId, siteIRI, label);
-            }
+            return new ReconItemIdValue(cell.recon, cell.value.toString());
         }
         throw new SkipSchemaExpressionException();
     }
 
+    @JsonProperty("columnName")
     public String getColumnName() {
         return columnName;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLanguageConstant.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLanguageConstant.java
index 2b3777d10..8fda71222 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLanguageConstant.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLanguageConstant.java
@@ -7,14 +7,12 @@ import com.fasterxml.jackson.annotation.JsonProperty;
 
 public class WbLanguageConstant extends WbLanguageExpr {
     
-    public static final String jsonType = "wblanguageconstant";
-    
     protected String _langId;
     protected String _langLabel;
     
     @JsonCreator
     public WbLanguageConstant(
-            @JsonProperty("lang") String langId,
+            @JsonProperty("id") String langId,
             @JsonProperty("label") String langLabel) {
         _langId = langId;
         _langLabel = langLabel;
@@ -24,10 +22,12 @@ public class WbLanguageConstant extends WbLanguageExpr {
         return _langId;
     }
     
+    @JsonProperty("id")
     public String getLang() {
         return _langId;
     }
     
+    @JsonProperty("label")
     public String getLabel() {
         return _langLabel;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLanguageVariable.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLanguageVariable.java
index be3b65492..e64e6917f 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLanguageVariable.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLanguageVariable.java
@@ -22,13 +22,14 @@ public class WbLanguageVariable extends WbLanguageExpr {
     public String evaluate(ExpressionContext ctxt)
             throws SkipSchemaExpressionException {
         Cell cell = ctxt.getCellByName(getColumnName());
-        if (cell != null) {
+        if (cell != null && cell.value != null && !cell.value.toString().isEmpty()) {
             // TODO some validation here?
             return cell.value.toString();
         }
         throw new SkipSchemaExpressionException();
     }
 
+    @JsonProperty("columnName")
     public String getColumnName() {
         return columnName;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLocationConstant.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLocationConstant.java
index e80867641..f45329a3f 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLocationConstant.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLocationConstant.java
@@ -55,6 +55,7 @@ public class WbLocationConstant extends WbLocationExpr {
         return parsed;
     }
     
+    @JsonProperty("value")
     public String getValue() {
         return value;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLocationVariable.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLocationVariable.java
index be4e8c15d..f1c7bdc7d 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLocationVariable.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbLocationVariable.java
@@ -35,6 +35,7 @@ public class WbLocationVariable extends WbLocationExpr {
         throw new SkipSchemaExpressionException();
     }
 
+    @JsonProperty("columnName")
     public String getColumnName() {
         return columnName;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbNameDescExpr.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbNameDescExpr.java
index 26eb196c8..10e689b43 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbNameDescExpr.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbNameDescExpr.java
@@ -51,6 +51,7 @@ public class WbNameDescExpr extends JacksonJsonizable {
         return type;
     }
 
+    @JsonProperty("value")
     public WbMonolingualExpr getValue() {
         return value;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbPropConstant.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbPropConstant.java
index 4da1cfa06..5fa3c530c 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbPropConstant.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbPropConstant.java
@@ -1,7 +1,6 @@
 package org.openrefine.wikidata.schema;
 
-import org.openrefine.wikidata.schema.entityvalues.TermedPropertyIdValue;
-import org.wikidata.wdtk.datamodel.implementation.PropertyIdValueImpl;
+import org.openrefine.wikidata.schema.entityvalues.SuggestedPropertyIdValue;
 import org.wikidata.wdtk.datamodel.interfaces.PropertyIdValue;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
@@ -27,18 +26,20 @@ public class WbPropConstant extends WbPropExpr {
 
     @Override
     public PropertyIdValue evaluate(ExpressionContext ctxt) {
-        return new TermedPropertyIdValue(pid, ctxt.getBaseIRI(), label);
+        return new SuggestedPropertyIdValue(pid, ctxt.getBaseIRI(), label);
     }
     
+    @JsonProperty("pid")
     public String getPid() {
         return pid;
     }
 
-    
+    @JsonProperty("label")
     public String getLabel() {
         return label;
     }
     
+    @JsonProperty("datatype")
     public String getDatatype() {
         return datatype;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbReferenceExpr.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbReferenceExpr.java
index 22e3fffc7..646da1b20 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbReferenceExpr.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbReferenceExpr.java
@@ -41,6 +41,7 @@ public class WbReferenceExpr extends JacksonJsonizable {
         }
     }
 
+    @JsonProperty("snaks")
     public List<WbSnakExpr> getSnaks() {
         return snakExprs;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbSnakExpr.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbSnakExpr.java
index 27ab015d3..f82cccffa 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbSnakExpr.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbSnakExpr.java
@@ -30,10 +30,12 @@ public class WbSnakExpr extends JacksonJsonizable {
         return Datamodel.makeValueSnak(propertyId, evaluatedValue);
     }
 
+    @JsonProperty("prop")
     public WbPropExpr getProp() {
         return prop;
     }
 
+    @JsonProperty("value")
     public WbValueExpr getValue() {
         return value;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStatementExpr.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStatementExpr.java
index 070e636a5..6e40130cc 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStatementExpr.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStatementExpr.java
@@ -103,10 +103,12 @@ public class WbStatementExpr extends JacksonJsonizable {
         return mainSnakValueExpr;
     }
 
+    @JsonProperty("qualifiers")
     public List<WbSnakExpr> getQualifiers() {
         return qualifierExprs;
     }
 
+    @JsonProperty("references")
     public List<WbReferenceExpr> getReferences() {
         return referenceExprs;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStatementGroupExpr.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStatementGroupExpr.java
index 7f446ec90..d5d619c71 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStatementGroupExpr.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStatementGroupExpr.java
@@ -45,10 +45,12 @@ public class WbStatementGroupExpr extends JacksonJsonizable {
         }
     }
 
+    @JsonProperty("property")
     public WbPropExpr getProperty() {
         return propertyExpr;
     }
 
+    @JsonProperty("statements")
     public List<WbStatementExpr> getStatements() {
         return statementExprs;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringConstant.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringConstant.java
index 8c57ed308..e05f76adb 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringConstant.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringConstant.java
@@ -21,6 +21,7 @@ public class WbStringConstant extends WbStringExpr {
         return Datamodel.makeStringValue(value);
     }
     
+    @JsonProperty("value")
     public String getValue() {
         return value;
     }
diff --git a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringVariable.java b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringVariable.java
index 5938a0017..6989189ad 100644
--- a/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringVariable.java
+++ b/extensions/wikidata/src/org/openrefine/wikidata/schema/WbStringVariable.java
@@ -30,6 +30,7 @@ public class WbStringVariable extends WbStringExpr {
         throw new SkipSchemaExpressionException();
     }
 
+    @JsonProperty("columnName")
     public String getColumnName() {
         return columnName;
     }