The rules for 2011 are not yet finalized. The NACLO committee may make minor changes to the rules in the next few months.

You may also find these rules, along with all other essential information about the contest, in the printer-friendly NACLO Handbook (Word file).


The NACLO competition is for high-school students, which also allows the participation of middle-school students. It consists of two rounds, called the Open Round and Invitational Round.

Open Round (February 2, 2010): The first round is open to all interested middle-school and high-school students; its purpose is to identify the strong contestants who advance to the second round. The judges expect that about one hundred contestants will advance to the Invitational Round.

Invitational Round (March 10, 2010): The second round is for the contestants who have advanced from the first round, and the problems at this competition are harder than the Open Round problems. The purpose is to select national winners, who will be eligible to participate in the International Linguistics Olympiad (ILO).

Problems and solutions

  • The Open Round is three hours long, whereas the Invitational Round is five hours long. The judges have the authority to lengthen either competition in the event of unforeseen circumstances.
  • The contestants should submit all their solutions in writing, using a black nonerasable pen, and ensure that their handwriting is legible. The use of a black pen is essential to ensure legible photocopying or scanning of the solutions, which may be done to streamline the grading process.
  • The contestants should write their names and registration numbers on every page of the booklet, and they should write their solutions in the appropriate spaces, provided in the booklet; the judges will grade only legible solutions. If the space in the booklet is insufficient, contestants may use extra blank sheets to write their solutions. If they use extra sheets, they should write their names, registration numbers, and problem numbers on every sheet; use only one side of each sheet for the solution; and use different sheets for different problems. After the competition, the contest organizers will photocopy or scan the submissions and send different problems to different graders. If a contestant uses both sides of a sheet, the text on the back will be lost during the photocopying or scanning.
  • The contestants may solve the given problems in any order, and they should try to solve as many problems as possible. Most problems include "practice" and "theory" questions; the practice parts are worth about 60% of the score, and the theory parts are worth about 40%. Contestants may receive partial credit for providing an incomplete solution to a problem, or specific ideas for solving it. Thus, if they have ideas for solving a problem, they should write them even if they have not been able to develop a complete solution.

Allowed and disallowed materials

  • The contestants should bring their own paper and black pen, and may optionally bring pencils or other writing instruments for scratch work. The facilitators will provide additional paper as necessary.
  • The contestants should write their solutions in black ink, and may use pencils only for scratch work. They may use blank paper for scratch work; however, they should copy their final solutions into the spaces provided in the problem booklet, and they may enclose additional sheets only if the space in the booklet is insufficient.
  • The contestants may not use any electronic devices except basic wristwatches. In particular, they may not use calculators, computers, palm pilots, cell phones, pagers, or wristwatches with built-in calculators. Attempts to use electronic devices will normally lead to disqualification. If a contestant has any medical electronic devices, required for health reasons, she or he should notify the facilitators about it before the contest.
  • The contestants may not use any written or printed materials, such as books or their own notes produced before the contest.

Conduct during the contest

  • The contestants should follow all instructions of the facilitators; if they have questions about the rules or conduct during the contest, they should raise their hand and ask a facilitator.
  • The contestants may not talk with anyone except facilitators, and may not collaborate with each other. Attempts to communicate with other contestants will normally lead to disqualification.
  • Any bags should be placed under the seats before the contest, and may not accessed during the contest. Thus, the contestants should get all required materials from their bags before the contest.
  • If a contestant has a cell phone, pager, or any other sound-emitting device, it should be turned off before the contest; note that switching it to the silent mode is not sufficient.
  • The contestants may take bathroom breaks during the contest; however, they may not take their bags, any electronic devices, problem booklets, or their notes with them when temporarily leaving the room. Also, two contestants may not take a bathroom break at the same time.
  • The contestants may bring snacks into the contest site and eat during the contest, but they should be considerate of others. In particular, they should avoid "noisy" foods, such as foil-wrapped chocolates, and foods with a strong smell. The local facilitators have the authority to override this rule and prohibit snacks at specific sites. Even if the facilitators allow snacks, they have the authority to remove any types of food from the contest site if they feel that these types of food may distract other contestants.
  • If some contestant arrives late, they may still participate in the contest; however, they may not ask facilitators to repeat any instructions or announcements that have been missed due to the late arrival. Also, they may not ask for time extension in the end of the contest, which means that they will have less time than the other contestants.

Questions during the contest

  • If a contestant has a question, she or he should raise a hand, and one of the facilitators will answer the question. When talking with a facilitator, contestants should keep their voice low, to make sure that they do not distract others and do not accidentally provide a hint for solving any problems.
  • If a contestant needs a clarification for a specific problem, the facilitator will need to contact the judges via email, which means that an immediate answer may not be available. Please note that local facilitators are unable to provide answers without contacting the judges. If the judges agree that the problem requires a clarification or correction, they will normally announce it to all contestants.
  • If the judges feel that an answer is already contained in the booklet, or that a contestant is asking for a hint on how to solve the problem, they may refuse to answer the question.
Note to facilitators: The contest orginizers will provide the e-mail address for clarification questions. Please do not attempt to answer questions about problems without contacting the judges. Also, please monitor your e-mail for possible clarifications and corrections. Please remember that even a minor comment may sometimes give your local contestants an advantage over others, and it may also confuse contestants.


  • Every problem will be worth a specified number of points; harder problems are generally worth more points.
  • The judges will score each solution based on its correctness, quality, and clarity, and determine the overall score as the sum of solution scores; see the NACLO scoring page for more details. They will try (but do not guarantee) to complete the scoring and announce the results within three weeks after the competition.
  • The judges are solely responsible for scoring the solutions, ruling on unforeseen situations, and selecting the winners; their decisions are final.

Special needs

If some contestants have special needs, they should notify the contest organizers as soon as possible, and the organizers will try to accommodate them. The contestants should discuss all their special needs before the contest.

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