diff --git a/lib/DataHarmonizer.js b/lib/DataHarmonizer.js
index b34a1822..4c012c40 100644
--- a/lib/DataHarmonizer.js
+++ b/lib/DataHarmonizer.js
@@ -1763,14 +1763,27 @@ class DataHarmonizer {
   }
 
   /**
+   * Given a table row, output a value based on the following conditional:
+   * ```
+   * if (value in headerNameToCheck == valToMatch) {
+   *   return value in headerNameToOutput;
+   * } else {
+   *   return "";
+   * }
+   * ```
    * TODO is there any need for additional complexities in getMappedField?
    *   i.e., transforming field
-   * @param headerNameToCheck
-   * @param valToMatch
-   * @param headerNameToOutput
-   * @param inputRow
-   * @param sourceFieldNameMap
-   * @return TODO
+   * @param {string} headerNameToCheck Field name of user-inputted vals to check
+   * against `valToMatch`.
+   * @param {string} valToMatch Value to match user-inputted vals against during
+   * conditional.
+   * @param {string} headerNameToOutput Field name of user-inputted vals to
+   * return if conditional is satisfied.
+   * @param {string[]} inputRow Table row.
+   * @param {Object<string, number>} sourceFieldNameMap `getFieldNameMap` return
+   * val.
+   * @return {string} `valToMatch` if condition is satisfied; empty str
+   * otherwise.
    */
   getIfThenField(
     headerNameToCheck,
@@ -1785,12 +1798,17 @@ class DataHarmonizer {
   }
 
   /**
-   * TODO
-   * @param headerNameToCheck
-   * @param matchedValsSet
-   * @param inputRow
-   * @param sourceFieldNameMap
-   * @return {string}
+   * Given a table row, find the intersection of user-inputted values in
+   * `headerNameToCheck` and vals in `matchedValsSet`.
+   * @param {string} headerNameToCheck Field name of user-inputted vals to
+   * intersect against `matchedValsSet`.
+   * @param {Set<string>} matchedValsSet Set of values that user-inputted vals
+   * are intersected against.
+   * @param {string[]} inputRow Table row.
+   * @param {Object<string, number>} sourceFieldNameMap `getFieldNameMap` return
+   * val.
+   * @return {string} Intersection of user-inputted values in
+   * `headerNameToCheck` and vals in `matchedValsSet`.
    */
   getMatchedValsField(
     headerNameToCheck,
@@ -1809,11 +1827,14 @@ class DataHarmonizer {
   }
 
   /**
-   * TODO
-   * @param headerNamesToCheck
-   * @param inputRow
-   * @param sourceFieldNameMap
-   * @return {string}
+   * Given a table row, and an ordered collection of field names, return the
+   * first non-null field val.
+   * @param {string[]} headerNamesToCheck Field names of user-inputted vals to
+   * check for non-null vals, in 0-indexed order.
+   * @param {string[]} inputRow Table row.
+   * @param {Object<string, number>} sourceFieldNameMap `getFieldNameMap` return
+   * val.
+   * @return {string} First non-null val in `headerNamesToCheck`.
    */
   getFirstNonNullField(headerNamesToCheck, inputRow, sourceFieldNameMap) {
     const nullValsSet = new Set(