diff --git a/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/CSV.kt b/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/CSV.kt
index e43ca3b..a36caa2 100644
--- a/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/CSV.kt
+++ b/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/CSV.kt
@@ -1,5 +1,8 @@
 package uk.co.neviyn.observationdatabase
 
+/**
+ * Header line for a CSV file in the format of the standard observation database
+ */
 fun csvHeaderString(): String {
     return "Ob ID,Observerfull,Observer,obDate,Title,Type,Department,Station,Station Focus,Scores-Monitoring,Scores-Control Procedural," +
         "Scores-Control,Scores-Conservatism,Scores-Teamwork Comms,Scores-Teamwork Leadership,Scores-Teamwork Workload,\"Scores-Knowledge, Skills and Attitudes\"," +
@@ -9,6 +12,9 @@ fun csvHeaderString(): String {
         "Develop-Teamwork Leadership,Develop-Teamwork Workload,\"Develop-Knowledge, Skills and Attitudes\""
 }
 
+/**
+ * Given the observations in [data], output a string that aligns the data with the format described in csvHeaderString()
+ */
 fun observationsToCSV(data: List<Observation>): String {
     val builder = StringBuilder(csvHeaderString())
     data.forEach {
diff --git a/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/Email.kt b/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/Email.kt
index f6f53b7..d3954f1 100644
--- a/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/Email.kt
+++ b/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/Email.kt
@@ -17,6 +17,9 @@ class Email {
 
     private val logger: Logger = LoggerFactory.getLogger(javaClass)!!
 
+    /**
+     * Send observation data to the configured email address
+     */
     fun sendObservationData(observations: List<Observation>) {
         if (observations.isEmpty()) {
             logger.error("Cannot send observations email containing no observations!")
diff --git a/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/GroupSessionManager.kt b/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/GroupSessionManager.kt
index 4a9fba8..5c678ef 100644
--- a/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/GroupSessionManager.kt
+++ b/backend/src/main/kotlin/uk/co/neviyn/observationdatabase/GroupSessionManager.kt
@@ -17,6 +17,9 @@ object GroupSessionManager {
     var scenarioTitles: List<String>? = null
     var observations: MutableMap<String, GroupObservation> = mutableMapOf()
 
+    /**
+     * Start a new group session
+     */
     fun startNewSession(site: Site, tutors: Set<Tutor>, trainingType: TrainingType, scenarioTitles: List<String>): Int {
         logger.info("Starting new Group Session")
         logger.debug("Previous ID was $sessionId")
@@ -34,6 +37,9 @@ object GroupSessionManager {
         return sessionId
     }
 
+    /**
+     * Invalidate the current session
+     */
     fun invalidate() {
         this.site = null
         this.tutors = null
@@ -42,14 +48,23 @@ object GroupSessionManager {
         this.observations = mutableMapOf()
     }
 
+    /**
+     * Check if the current session has [sessionId] and is valid
+     */
     fun isValid(sessionId: Int): Boolean {
         return isValid() && sessionId == this.sessionId
     }
 
+    /**
+     * Check if the current session is valid
+     */
     fun isValid(): Boolean {
         return site != null && tutors != null && trainingType != null && scenarioTitles != null
     }
 
+    /**
+     * Return the data contained in the current session in the scenario format
+     */
     fun asScenarioView(): MutableMap<String, MutableList<Scenario>> {
         val output: MutableMap<String, MutableList<Scenario>> = mutableMapOf()
         scenarioTitles?.forEach { title ->
@@ -63,6 +78,9 @@ object GroupSessionManager {
         return output
     }
 
+    /**
+     * Check whether the data currently submitted for a session is all valid
+     */
     fun dataComplete(): Boolean {
         if (observations.isEmpty()) {
             logger.warn("Observations is currently empty")
@@ -77,11 +95,20 @@ object GroupSessionManager {
         return true
     }
 
+    /**
+     * Update the stored data for the individual submitting the [input] data
+     */
     fun updateObservationData(input: GroupObservation) {
         observations[input.person] = input
     }
 
+    /**
+     * Check whether [name] exists as a participant in this session
+     */
     fun participantExistsInSession(name: String): Boolean = observations.containsKey(name)
 
+    /**
+     * Get the observation data stored in this session for [name]
+     */
     fun getObservationDataForParticipant(name: String): GroupObservation? = observations[name]
 }
\ No newline at end of file