diff --git a/stellarphot/io/aavso.py b/stellarphot/io/aavso.py
index 66d7b153..99b6737c 100644
--- a/stellarphot/io/aavso.py
+++ b/stellarphot/io/aavso.py
@@ -1,5 +1,9 @@
 # Class to representa file in AAVSO extended format
-from dataclasses import dataclass
+from dataclasses import dataclass, field
+from typing import Union
+from pathlib import Path
+from importlib import resources
+import yaml
 
 from astropy.table import Table
 
@@ -16,8 +20,46 @@ class AAVSOExtendedFileFormat:
     delim: str = ","
     date: str = 'HJD'
     obstype: str = 'CCD'
-    data: Table = Table()
+    variable_data: Table = field(default_factory=Table)
+    check_data: Table = field(default_factory=Table)
+    comparison_data: Union[Table, None] = None
+    ensemble: bool = False
 
     @property
     def type(self):
-        return self._type
\ No newline at end of file
+        return self._type
+
+    @property
+    def software(self):
+        return self._software
+
+    def set_data(self, destination, data,
+                 time='time', mag='mag', error='err', airmass='airmass'):
+        """
+        Set data for each thingy
+        """
+        # Standardize column order
+
+        standard_data = {
+            time: data[time],
+            airmass: data[airmass],
+            mag: data[mag],
+            error: data[error],
+        }
+        standard_data = Table(standard_data)
+        if destination == "variable":
+            self.variable_data = standard_data
+        elif destination == "check":
+            self.check_data = standard_data
+        elif destination == "comparison":
+            if self.ensemble:
+                raise ValueError("Cannot set comparison data for ensemble magnitudeas")
+            self.comparison_data = standard_data
+
+    def write(self, file):
+        p = Path(file)
+
+        # Make a table
+        table_description = resources.read_text('stellarphot.io', 'aavso_submission_schema.yml')
+        table_structure = yaml.safe_load(table_description)
+        print(table_structure['data'].keys())
\ No newline at end of file
diff --git a/stellarphot/io/tests/test_aavso.py b/stellarphot/io/tests/test_aavso.py
index 7bd01682..27a8cb67 100644
--- a/stellarphot/io/tests/test_aavso.py
+++ b/stellarphot/io/tests/test_aavso.py
@@ -13,10 +13,16 @@ def test_no_obscode_raises_error():
 def test_default_values():
     aef = AAVSOExtendedFileFormat(DEFAULT_OBSCODE)
     assert aef.delim == ","
-    assert len(aef.data) == 0
+    assert len(aef.variable_data) == 0
 
 
 def test_setting_type_raises_error():
     aef = AAVSOExtendedFileFormat(DEFAULT_OBSCODE)
     with pytest.raises(AttributeError, match="can't set attribute"):
-        aef.type = 'STD'
\ No newline at end of file
+        aef.type = 'STD'
+
+
+def test_writing():
+    aef = AAVSOExtendedFileFormat(DEFAULT_OBSCODE)
+    aef.write('foo.csv')
+    assert 0
\ No newline at end of file