The	  Electronic	  Journal	  for	
  English	
  as	  a	  Second	  Language	  	  	  	  Duolingo	  May	  2015	  –	  Volume	  19,	  Number	  1	  	
  Title	  Duolingo	  Author	  Duolingo	  Inc.	  

Contact	  Information	  https://www.duolingo.com/	  https://itunes.apple.com/us/app/duolingo-­‐learn-­‐languages-­‐for/id570060128?mt=8	  https://play.google.com/store/apps/details?id=com.duolingo&hl=en	  https://www.windowsphone.com/en-­‐us/store/app/duolingo-­‐learn-­‐languages-­‐for-­‐free/2d89520e-­‐d360-­‐4b5b-­‐ba5a-­‐5a15064aa935	
  Type	  General	  language	  learning	  app	  Platform	  Web	  browser,	  iOS,	  Android,	  Windows	  phone	  Current	  Up	  to	  date	  web	  browser,	  iOS	  7.0	  or	  later,	  Android,	  Windows	  Phone	  8.1	  Compatibility	
  Price	
  Free	  	  General	  Description	  Overview	  Boasting	   over	   20	   million	
   users,	   Duolingo	   is	   a	   browser-­‐based	   and	
   mobile	   application	  launched	   in	   2012	   that	
   allows	
   users	   to	   “Learn	   a	   language	   for	
   free.	   Forever”	   (Duolingo,	
  2014).	   Currently,	   full	   versions	   are	   available	   in	   Spanish,	   French,	   Italian,	   German,	  Portuguese,	   and	   English	   with	
   other	   languages	
   under	   development.	   Duolingo	
   calls	  language	   learning	   with	   the	   application	   “fun	   and	   addictive”	   as	   users	
   “earn	
   points	   for	  correct	   answers,	   race	   against	   the	
   clock,	   and	
   level	   up”	   (Duolingo,	
   2014).	   The	   company	
  prides	
  itself	  on	  “bite-­‐size,”	  “effective”	
  lessons	  that	  2it	  into	  your	  daily	  life	  (Duolingo,	  2014)	  and	
  claims	  the	
  program	  is	  more	  ef2icient	  for	  language	  learning	  than	  a	  university	
  course,	  estimating	   that	   34	   hours	
   using	   Duolingo	   is	   equivalent	   to	   the	   instruction	   provided	   in	   a	  16-­‐week	  university	  semester	  (Vesselinov	  &	  Grego,	  2012).	  
Duolingo	   is	   ad-­‐	   and	   cost-­‐free	   due	   to	   its	   monetization	   of	   built-­‐in	   user	   translations	   of	  webpages	   in	   immersion	   activities	   on	   the	   web	   version.	   Available	   as	   a	   browser-­‐based	  application	   or	   an	   iOS,	   Android,	   or	   Windows	
   Phone	   application,	   Duolingo	   uses	   a	   single	  TESL-­‐EJ	  19.1,	  May	  2015	  Duolingo/Cunningham	  	  1	  	  user	   account	
   setup	   by	   way	   of	   an	   email,	   Facebook,	   or	   Google	   account	   to	   sync	   progress	
  across	  all	  platforms.	  Since	  user	  experience	  and	  available	  features	  vary	
  across	  platforms,	  this	  review	  will	  focus	  on	  the	  iOS	  iPad	  version	  of	  Duolingo,	
  Apple’s	  2013	  App	  of	  the	  year	  (Duolingo,	  2014)	  in	  English	  (L1)	  with	
  French	  as	  the	
  target	  language	  (L2).	  
Structure	  The	
   app’s	   home	
   screen	   displays	   Duolingo’s	   language-­‐learning	   tree	   (see	   Figure	   1).	   The	  one	   to	   three	   circles	   in	   each	   row	   of	   the	   tree	   represent	
   units	   that	   must	   be	   successfully	  completed	
   before	   a	   user	   can	   move	   to	   the	   next	   row	   of	   activities.	
   Units	   tend	   to	   be	  semantically	  or	  grammatically	
  themed,	  with	  content-­‐oriented	
  themes	  such	  as	  “animals”	  or	   grammatically	   focused	
   themes	   such	   as	   “possessives.”	   Completion	   of	   all	   68	   units	   is	  equated	   with	   a	   high-­‐intermediate,	   or	   B2	   on	   the	   CEFR,	
   level	   of	   pro1iciency	   according	   to	  Duolingo’s	
  founder	  (Vesselinov,	
  2014).	  

Figure	  1.	  The	  main	  screen	  language-­‐learning	  tree	  	
  Each	   unit	   contains	   a	   linear	   sequence	   of	   lessons,	   each	   made	   up	   of	   a	   set	   of	   chronologically	  ordered	  activities	  facilitated	  in	  the	  L1.	
  Despite	  Duolingo	  claiming	  “a	  variety	  of	  speaking,	  listening,	   translation	   and	   multiple	
   choice	   challenges,”	   (“Duolingo,”	
   2014)	   the	   vast	  majority	   of	   these	   activities	   involve	   translation	   of	   a	   sentence	   or	   phrase	   usually	   through	  TESL-­‐EJ	  19.1,	  May	  2015	  Duolingo/Cunningham	  	  2	  	  selection	  from	  a	  word	  bank	  as	  seen	  in	  Figure	  2.	  Other	  exercises	
  include	
  verbal	  repetition	  of	   a	   spoken	   or	   written	   L2	   structure	   and	   dictation,	
   which	
   allows	   for	   multispeed	
   audio	  replay.	  New	  L2	  words	  give	  the	  user	  the	  ability	  to	  access	
  various	  highlighted	  L1	  pop-­‐up	
  gloss	   options,	   and	   most	   exercises	
   offer	   optional	   corresponding	
   spoken	   L2	   text.	   All	  exercises	
   offer	   immediate	
   color	   and	
   sound	
   coded	   textual	   animated	   feedback	   on	  correctness,	   and	
   items	   answered	   incorrectly	   may	   be	   repeated	   later	   in	   the	   lesson.	   Each	
  lesson	
   allots	   a	   given	   a	   number	   of	   hearts,	   usually	
   three	   to	   four,	   that	   are	   eliminated	   for	  each	  incorrect	
  answer.	  When	  no	  hearts	
  remain,	  incorrect	  responses	
  result	  in	  restarting	  the	   lesson.	   Progress	   through	   a	   lesson	   is	   visually	   tracked	   by	   way	   of	   an	   incremental	  progress	  bar	  at	  the	  top	  of	  the	  screen.	  

Figure	  2.	
  Example	  translation	  activity	  	  	  Correct	   responses	   and	   completed	   lessons,	
   units,	   and	
   levels	   earn	   language	   experience	  points	   used	   to	   track	   progress.	   In	   addition,	   accomplishments,	   such	   as	   completion	   of	   a	  unit,	   are	   rewarded	   with	   lingots,	   Duolingo’s	   own	   currency	
   which	   can	   be	   used	   at	   the	  lingots	  shop	  to	  buy	  extra	
  hearts	  or	  out2its	  for	  the	  Duolingo	
  mascot	  (see	
  Figure	  3).	  Users	  can	   track	
   their	   progress	   on	   a	   line	
   graph	
   found	   under	   the	   pro3ile	   link	   at	   the	   top	   of	   the	  TESL-­‐EJ	  19.1,	  May	  2015	  Duolingo/Cunningham	  	  3	  	  screen.	  The	  pro,ile	  link	  also	
  allows	  users	  to	  change	  their	  goals	  or	  settings,	  see	  the	
  weekly	  leaderboard	  of	  friends’	  progress,	  or	  add	  additional	
  friends	  (see	
  Figure	  4).	  

Figure	  3.	  A	  screenshot	  of	  the	  Duolingo	
  lingots	  shop	  TESL-­‐EJ	  19.1,	  May	  2015	  Duolingo/Cunningham	  	  	  4	  	  Figure	  4.	
  Pro$ile	  tab	  of	  Duolingo	  iPad	  app	  	  Evaluation	  Technological	  Features	  When	   it	   comes	   to	   technological	   considerations,	   such	   as	   layout,	
   sound	   and	
   visual	  affordances,	   Duolingo	   capitalizes	   on	   some	   features	
   while	   also	   showing	   room	   for	  improvement.	  Duolingo	  has	  taken	
  obvious	  care	  to	  simplify	  the	  screen	
  layout	  for	
  mobile	  devices,	   allowing	   for	   both	   vertical	   and	   horizontal	   orientation	   of	   the	   fairly	   intuitive	   L1	  interface	  with	
  simple	  navigation.	
  Colors	  are	  used	  effectively	  to	  show	  language	  learners’	  progress	   in	   a	   visual	   way	   by	   coloring	   accessible	   unit	
   icons	   and	   presenting	   currently	  inaccessible	
   units	   in	   gray	
   scale	   (see	   Figure	   1	   above).	   This	   is	   a	   welcome	
   design	
   choice	
  given	  that	  the	  “tree”	  or	  unit	  map	  is	  several	  pages	  long.	  
The	  sound	
  quality	  is	  clear	  overall,	
  though	  it	  occasionally	
  sounds	  computer	  generated	  and	  sometimes	   experiences	   lag	   or	   fails	   to	   play	   in	   some	
   audio-­‐augmented	
   touch-­‐based	  activities.	  The	  program	  takes	  advantage	  of	  the	  microphone	  for	
  users’	
  spoken	  translations	  and	
   seems	
   adept	   at	   accepting	   less	   than	   perfect	   learner	   pronunciation.	   Microphone	   lag	   is	  rare,	   and	   the	   interface	   shows	   a	   visualization	   of	   recorded	
   volume	   for	   immediate	   user	  TESL-­‐EJ	  19.1,	  May	  2015	  Duolingo/Cunningham	  	  5	  	  con$irmation	   (see	   Figure	   5).	   One	   strength	   of	   the	   speaking	   interface	   is	   the	   button	   that	
  allows	  users	  to	  skip	  audio-­‐based	  activities	  for	  a	  speci/ied	
  period	  of	  time	  or	  turn	  them	  off	  entirely.	  This	  can	  be	  a	  valuable	
  option	  when	  using	  the	  app	  in	  public	  and	  desiring	  muted	
  audio.	  

Figure	  5.	  Audio	  recording	  interface	  	  The	  app	  also	  effectively	  utilizes	  the	  automation	  and	
  social	  capacity	  of	  mobile	
  devices	  to	  motivate	
   users	   and	
   track	   progress,	   capitalizing	   on	   such	   functions	   to	   offer	   users	   the	  ability	   to	   compete	   with	   friends	
   using	   the	   program,	   and	   monitor	   achievements	   through	  on	   screen	   pop-­‐up	   and	
   email	   reminders	   to	   help	
   users	   stay	   on	   track	   with	
   their	  individualized	
  goals.	  However,	  considering	  Duolingo’s	  use	  of	  CALL	  affordances	  broadly,	  the	  app	
  ignores	  the	  effectiveness	  of	  input	  elaboration	  (Chapelle,	
  2003),	  limiting	  its	  use	  of	  input	   enhancement	   to	   salience	   and	   modi0ication.	   A	   moderate	
   level	   of	   salience	   is	   realized	  largely	   through	   repetition	   and	   some	
   marked	
   input,	   such	   as	   the	   highlighted	   new	  vocabulary,	
   while	   L1	   pop	   up	   glosses	   and	   occasional	
   images	   comprise	   the	   primary	  attempts	   at	   modi+ication,	   leaving	   much	   to	   be	   desired	   in	   directing	   learner	   attention	   to	  input.	   The	   expansion	   of	   input	   enhancements	   to	   include	   elaboration	
   could	   provide	   the	  TESL-­‐EJ	  19.1,	  May	  2015	  Duolingo/Cunningham	  	  6	  	  context	   and	   explanation	
   needed	   for	   a	   more	   complete	   understanding	   of	   the	
   target	  language.	  
Pedagogical	  Considerations	  Pedagogically,	   Duolingo	
   falls	   into	   digital	   game	   based	   learning	
   (DGBL)	   and	   adheres	   to	  many	   of	   its	   tenets	
   fairly	
   well.	   Animation,	
   sound	   effects,	   rewards	   for	   achievement,	   and	  competition	   with	   others,	   all	   recognized	   elements	   of	   successful	   DGBL	   (Intratat,	
   2011;	  Prensky,	  2003),	  are	  incorporated	  effectively.	  However,	  Duolingo	  falls	  short	  of	  Prensky’s	  (2003,	  2005)	  requirement	  that	  DGBL	
  attain	  a	  high	  level	  of	  both	  engagement	
  (play)	  and	  learning.	  While	  Duolingo	
  begins	  to	  address	  both	  of	  these	
  areas,	  it	  fails	  to	  do	  so	  at	  a	  high	  level.	   The	   incorporation	   of	   more	   game-­‐like	   aspects,	
   input	   elaboration,	   or	   integrated	  language	   use	   scenarios	
   could	
   boost	   potential	
   users’	
   level	   of	   engagement	   and	   learning	  potential.	  
The	
   strict	
   linear	   structuring	   of	   Duolingo	   suggests	   a	   clearly	   envisioned	   curriculum,	   but	
  apart	  from	  incrementally	  introducing	  vocabulary	  and	
  simple	  grammatical	  structures,	  the	  sequencing	   of	   material	   can	   feel	   arbitrary	   to	   a	   learner.	   Grammatical	   structures	   provide	  continuity,	   but	   this	
   often	   gives	   much	   of	   the	   language	   a	   fabricated	
   feel.	   This	   lack	   of	  authenticity	   is	   furthered	   by	   Duolingo’s	
   dearth	   of	   opportunities	   for	   meaningful	  communication,	
  leaving	  the	
  program	  in	  the	  grammar	  translation	  era	  with	  a	  behaviorist	
  focus	   on	   repetition.	   More	   modern	   interactionist	   and	   sociocultural	   SLA	   expectations	   of	  negotiated	   meaning	   in	   context	   and	   multiple	
   forms	   of	   interaction	   are	   not	   met,	   as	   the	  program	
   relies	
   solely	   on	   small,	   disconnected,	   and	   decontextualized	
   chunks	   of	   isolated	  language;	  this	  decontextualization	  subsequently	  restricts	
  meaning	
  making.	  In	  the	  worst	
  cases,	  such	  isolated	  language	
  appears	  to	  make	
  little	
  sense,	  such	  as	  “he	  owes	  a	  chicken.”	  Without	   the	   use	   of	   input	   elaboration	   or	   context,	   the	   user	   is	   left	   not	   knowing	   whether	  such	   examples	   are	   as	   odd	   as	   they	   seem	   or	   if	   they	
   might	   hold	   specialized	   meaning	   in	  particular	  contexts.	  Many	  sentences,	  such	  as	  “I	  am	  a	  lion,”	  “he	  has	  a	  tiger,”	  or	  “it’s	
  eating	  a	  butter&ly,”	  seem	  to	  have	  been	  included	  not	  for	  their	
  utility	  or	  authenticity,	  but	
  rather	  to	  mimic	
  simple	
  grammar	  constructions	  from	  previous	
  units,	  such	  as	  the	  patterns	  “I	  am	  a	  boy,”	   “he	   has	   an	   apple,”	   and	   “he	   is	   eating	   an	   apple.”	
   While	   this	   may	
   serve	   to	   reinforce	   the	  construction,	   the	
   result	   is	   a	   series	   of	   odd	   sentences	   that	
   often	   lack	   relevance	   for	   a	  learner.	  This	  is	  a	  serious	  weakness	  of	  the	  app	  from	  a	  DGBL	  perspective,	  as	  relevance	  is	  the	  dominant	  predictor	  of	  user	  satisfaction	  (Huang,	
  Huang,	  &	  Tschopp,	
  2010).	
  Target	  Use	  Target	
   users	   of	   the	   app	
   would	   be	   autonomous	
   users	   with	   some	   existing	
   level	   of	  motivation	   or	   curiosity	   for	   language	
   study	   who	   are	   seeking	   to	   refresh	
   basic	   skills.	
   Those	  who	   can	   convince	   friends	   to	   study	   and	   compete	   with	   them	   can	   take	   advantage	   of	   the	  social	  motivation	  features	  and	
  perhaps	
  receive	  more	
  bene4it	  from	  use	  of	  the	  app.	  
However,	  due	  to	  the	  highly	  structured	
  linear	
  nature	  of	  the	  program,	  Duolingo	  would	  be	  dif$icult	   to	   incorporate	   into	   a	   classroom	   setting	   and	
   would	   not	   be	   a	   good	   match	   for	
  highly	   independent	
   users	   looking	   for	   individualized	   or	   5lexible	   learning	   opportunities.	
  Those	
  looking	  for	  advanced	  pro0iciency	  practice	  or	  authentic	  language	  examples	  will	  not	  !ind	  this	  app	  a	  suitable	  !it.	  The	  Duolingo	  app	  is	  probably	  best	  used	
  as	  a	  supplement	  to	  other	  language	  learning	  materials	  that	  offer	  more	  contextualized	  authentic	  language	  use.	
  TESL-­‐EJ	  19.1,	  May	  2015	  Duolingo/Cunningham	  	  7	  	  Duolingo	   can	   be	   viewed	   as	   a	   basic	
   mobile	   game	   that	   may	
   offer	   some	
   simple	   language	  learning	  bene*its.	  
Summary	  Overall,	   Duolingo	
   offers	   a	   fairly	   convenient,	
   free,	   and	
   basic	
   mobile	   learning	   application	
  which	  contains	  motivational	  DGBL	  features	  that	  give	  it	  enough	  of	  an	  addictive	  edge	  for	  many	   learners	   to	   stay	   engaged.	   However,	   its	   strict	
   linear	   curriculum,	   lack	   of	   authentic	  language,	  and	
  limited	  assortment	  of	  activities	
  prevent	  its	  full	  realization,	  relevance,	  and	  utility	
  as	  a	  DGBL	  opportunity.	  Its	  design	  makes	  Duolingo	  a	  solid	
  choice	  for	  independent	  supplemental	  practice,	  but	  acts	  more	
  as	  a	  fun	  refresher	  than	  a	  comprehensive	  language	  learning	  experience.	  

References	  Chapelle,	  C.A.	
  (2003).	
  English	  language	  learning	  and	  technology.	  Lectures	  on	  applied	  linguistics	  in	  the	  age	  of	  information	  and	  communication	  technology	  (Vol.	  7).	  
Philadelphia:	  John	  Benjamins	  Publishing	  Company.	  
Duolingo.	
  (2014).	  Retrieved	  September	  8,	  2014,	  2014,	  from	  http://www.duolingo.com	  Duolingo.	
  (2014,	  Sept.	  16,	  2014).	  Duolingo-­‐learn	  languages	  for	  free.	  Retrieved	  Oct.	  1,	  2014,	  2014,	  from	  https://itunes.apple.com/us/app/duolingo-­‐learn-­‐languages-­‐for/id570060128?mt=8	
  Huang,	  W.-­‐H.,	
  Huang,	  W.-­‐Y.,	  &	  Tschopp,	  J.	
  (2010).	  Sustaining	  iterative	  game	  playing	  processes	  in	  DGBL:	  The	  relationship	
  between	  motivational	  processing	  and	  outcome	  processing.	  Computers	  &	  Education,	
  55(2),	  789-­‐797.	  
doi:http://dx.doi.org/10.1016/j.compedu.2010.03.011	  Intratat,	  C.	
  (2011).	  Alternatives	  for	
  making	  language	  learning	  games	  more	  appealing	  for	  self-­‐access	  learning.	
  Studies	  in	  Self-­‐Access	  Learning	  Journal:	
  Special	  issue	  on	  CALL,	  E-­‐Learning,	  and	  M-­‐Learning,	  2(3),	  136-­‐152.	  
Prensky,	  M.	
  (2003).	
  Digital	  game-­‐based	  learning.	  Computers	  in	  Entertainment,	  1(1),	  21.	  
Prensky,	  M.	
  (2005).	  Computer	  games	  and	  learning:	
  Digital	  game-­‐based	  learning.	  In	  J.	  
Rasessens	  &	  J.	  Goldstein	
  (Eds.),	  Handbook	  of	  computer	  game	  studies	  (pp.	  97-­‐122)	  .	  Cambridge,	  MA:	  MIT	
  Press.	  
Stevenson,	  S.	
  (2014).	  How	  do	  you	  say	  addictive	  in	  Spanish?	  The	  wonderful	  free	  language	  app	  that	  makes	  learning	  new	
  tongues	  incredibly	  fun.	
  Slate.	  
http://www.slate.com/articles/technology/technology/2014/01/duolingo_the_free_language_learning_app_that_s_addictive_and_fun.html	  Vesselinov,	  R.,	  &	  Grego,	  J.	
  (2012).	  Duolingo	  effectiveness	
  study.	  Retrieved	  from	  Duolingo	  website:	  http://static.duolingo.com/s3/DuolingoReport_Final.pdf	  	  	  	  TESL-­‐EJ	  19.1,	  May	  2015	  Duolingo/Cunningham	  	  8	  	
  About	  the	  Reviewer	  Kelly	   J	   Cunningham	  <kellyc@iastate.edu>	   is	   currently	   a	   PhD	   student	   in	   applied	  linguistics	   and	   technology	   at	   Iowa	
   State	   University	
   where	   she	   studies	   the	   effects	   of	  technology	  use	  in	  second	  language	
  writing	  feedback.	  	  	  	  	  	  Copyright	  ©	  1994	  -­‐	  2015	  TESL-­‐EJ,	  ISSN	  1072-­‐4303	  Copyright	  rests	  with	  the	  authors.	
  	  	  TESL-­‐EJ	  19.1,	  May	  2015	  Duolingo/Cunningham	  	  9