Duolingo Answer Feedback Redesign

Duolingo is a gamified language learning app with bite sized lessons that offer users a way to learn new languages. Users can practice vocabulary, grammar and pronunciation and also take language certification.

Project Background

I have been using Duolingo since 2016 because I have always been interested in learning new languages. Growing up in a multilingual country, I have always enjoyed getting to know how to have basic language skills that would help me interact with people who speak different languages. In high school and college, I took German as a foreign language and I often used Duolingo to practice.

While I love Duolingo, there were some issues that made the user experience slightly harder. As a user experience designer, I decided to take it upon myself to learn more about the problems users faced and then come up with suggestions that would improve the product experience. 

User Research

To find out if the main problems users faced, I looked at the App store reviews to see common complaints from users. I also created a questionnaire that I shared with other Duolingo users. In the questionnaire, I asked them what frustrated them the most about the app. 

User Problems

From my research on the App store reviews and questionnaire, I found out that a common problem was that users were frustrated that their correct answers were being marked wrong.

Below are some of the screenshots from App Store reviews of Duolingo.

From the screenshot above, we can observe that:
- User 1 is frustrated that they type the right answer but they are told that they got it wrong.
- User 2 claims that even when they get the exact answer as the one being provided, their answers still get marked as wrong.
- User 3 feels that the app does not accept answers that are correct.

My Experience

While using Duolingo, I’ve encountered situations when I thought I had the correct answer but my answer was marked as wrong. Most of the time, I found out later on that there was a tiny error that I did not see and it would have been easier for me to spot the error had it been highlighted. 


While there may be many reasons behind the complaints, my hypothesis is that the main issue might be brought by how incorrect answers are depicted on the app. 

Some of the common errors include
- Missing word(s)
- Wrong arrangement of word(s)
- Spelling errors

Missing Word(s)


This sentence is incorrect because one word “im” is missing.

The whole sentence under the correct solution is in red without highlighting the specific error in the user’s sentence.

This makes it hard for users to see when they make tiny errors like missing one or two words.


Instead of having the entire sentence under the correct solution in red, only make the section with the error to be in red and the correct sections to be in green.

This will help users quickly see the error so that they can rectify it later on.

Missing Word(s)


This sentence is incorrect because the user put the word “of” before “lot” and therefore had a wrong word arrangement. 

This can happen when the user is in a hurry or they suffer from learning disabilities.

Having the correct solution in red without showing the exact error can make it frustrating for users who may fail to see the error.


Instead of having the entire sentence under the correct solution in red, only make the section with the word arrangement error to be in red and the correct sections of the sentence to be in green.

This will help users see where they made a mistake easily so that they can learn and correct in the future.

Proposed Solution

As seen in the examples above, clearly highlighting the section with the error will make it easier for the users to know where they made a mistake.

This could be done by having the correct sections in green and only the section with the error in red.Users will be able to quickly know where the error is and what they can do to avoid making the same mistake.

This will prevent users from being frustrated and leaving the app. Instead, users will be excited to learn more and keep improving their language skills.

Measuring the impact of the proposed solution

To test the impact of the redesign, Duolingo can track:
- User retention rates and if they are increasing after the redesign
- The rate at which people are passing orvfailing the gamified test
- User satisfaction using App store reviews

Back to Top