diff --git a/app/controllers/personal_conferences_controller.rb b/app/controllers/personal_conferences_controller.rb
index e67ad96..9efd224 100644
--- a/app/controllers/personal_conferences_controller.rb
+++ b/app/controllers/personal_conferences_controller.rb
@@ -38,7 +38,7 @@ class PersonalConferencesController < ApplicationController
         when "publication_date"
           t << {"value" => (writing_conference.send(fs).strftime("%Y/%m/%d") rescue "")}
         when "author_type"
-          t << {"value" => (writing_conference.conference_author_types.collect{|cat| cat.title}.joint(", ") rescue "")}
+          t << {"value" => (writing_conference.conference_author_types.collect{|cat| cat.title}.join(", ") rescue "")}
         else
           t << {"value" => writing_conference.send(fs)}
         end
diff --git a/app/models/writing_conference.rb b/app/models/writing_conference.rb
index 6906f50..5b53a6d 100644
--- a/app/models/writing_conference.rb
+++ b/app/models/writing_conference.rb
@@ -118,7 +118,7 @@ class WritingConference
             when "paper_levels"
               pd_data << {"data_title" => ( !p.conference_paper_levels.blank? ? p.conference_paper_levels.collect{|x| x.title}.join(', ') : "")}
             when "author_type"
-              pd_data << {"data_title" => (p.conference_author_types.collect{|cat| cat.title}.joint(", ") rescue "")}
+              pd_data << {"data_title" => (p.conference_author_types.collect{|cat| cat.title}.join(", ") rescue "")}
             else
               pd_data << { "data_title" => p.send(t) }
           end