Here are few suggestions and feature requests, that I would like to see implemented, that could improve the user experience on Brilliant.
MCQ's should have the option of having one or more than one choices correct. This would increase the challenge of the problem, it would make it easy to make problems which have more than one choice correct, for example the questions in this set by Mursalin. It would also reduce the amount of people who solve the problem by just guessing. Since the number of combinations of answers that can be input increases, I feel the number of attempts could be increased to 3 tries per question. Also, the number of choices in each question could be decided by users while typing the problem. For example, some questions often have only 3 choices, whereas some might require 5 options.
I would like to see the activity tab on the profile page split up into categories like questions solved, solutions posted, notes created, questions shared, etc. It would make it easier to access all solutions, and problems written by a user. Also, it would be better, if it could show all the activity since the user joined Brilliant.org, because now, I can only see my activity till 2 weeks ago, and nothing before that. In addition, it would be great to have a more detailed analysis of the user's performance, with graphs if possible, showing no. of problems solved, the ratings and the points trend in each topic over a period of time. This could perhaps be private, and the user can see only his performance.
The started page becomes very long, and trying to find an old question can be very difficult. I think it would be better if instead of having a single page with infinite scrolling, it could show, for example, 20, or 50 problem on one page. One can directly jump to the next page or last page, instead of endlessly scrolling.
Only the rated problemsshow the topic name like algebra, combinatorics, etc in the home page. For unrated problems, the topic is visible only when the question is opened. It would be better if even the unrated problems could show the topic name without opening the questions.
The search result could show whether the problems in list is solved or not. An additional search filter of solved, unsolved, can be introduced to show only the solved or unsolved problems in the list.
Not all problems should be worth 100 points. Tougher problems must be worth more points than easier ones. It gives more incentive to solve tough problems.
It would be great to save full sets for later, instead of only questions and notes.
An increase in the limit of number of tags from 5 in problems, notes and sets.
The ability to see the Latex code used by others, in questions and solutions, so that others can learn from it.
And, finally, a Brilliant app for iPad.
Some of these suggestion might have already requested by other users.
I know these changes might not be practical or easy to implement, however I feel that these could improve this already amazing site. I hope that these suggestions are considered by the staff.
In conclusion, I would like to thank the Brilliant staff, who have been working so hard to make this site so wonderful and give us an outstanding experience!!!!!