Frequently Asked Questions

Why 2Sigma School?

Mastery Learning - We believe that every student can attain an A+ level mastery over subjects, regardless of where they are. Unfortunately, most students don’t realize their learning potential because of the one-size-fits-all approach to education in most schools.

Personalized - We take a personalized approach where the pace of instruction, the content, and the instructional approach are all aligned with the student’s needs. Instead of starting the curriculum at fixed boundaries, we assess the student with a test and customize the curriculum to cover prerequisite concepts that the student must know well in order to learn more advanced concepts. Whether your student needs 9 months to master the curriculum or only 6 months, our program will move at the pace that is right for your student.

Feedback - Our research backed approach emphasizes frequent assessments and immediate corrective feedback to reinforce concepts taught. Students get automated bite-sized assessments frequently to ensure a tight feedback loop. Our live classes are centered around feedback and engagement rather than one-way delivery of instructional content.

Engagement - Research has shown that students more fully harness their potential when they are accountable to their peers. Neither 1:1 tutoring, nor traditional large classrooms can support high quality student engagement for online classes. Our small and matched cohorts of 8-10 students are designed specifically to foster active engagement in an online learning environment.

Curated Content - We believe that every student deserves to get instructions on new concepts from one of the best teachers in the World. Since by definition, there can be only a handful of such exceptional teachers, we use high quality, pre-recorded lectures from hand-picked teachers where appropriate. This frees our instructors to focus on providing clarifications, engaging students in discussions, and ensuring student comprehension rather than delivering lectures as their primary task.

Computer Science is all we do, and that means your students are learning in an environment optimized for the discipline. Leveraging the deep expertise of our founding team and their experience working at some of the best software companies, our courses and educational tools are built to make computer programming fun and accessible to all students.

Some key differences between 2Sigma School’s approach and traditional schools (both physical and online schools) include:

  • Small live-classes (8-10 students) to maximize interaction with peers and instructors.
  • Adaptive learning that ensures students have achieved mastery on prerequisite concepts required to learn the advanced course. Students are tested and provided remediation instructions on such prerequisite concepts as needed.
  • Unique flipped classroom model where students learn from curated, personalized content and engage in live classes for discussions and clarifications.
  • High-quality, personalized feedback on all homework assignments and practice tests - because most of the learning happens from feedback on mistakes and misconceptions.
  • Safe online collaboration environment across a global community of 2Sigma School students.
  • Focused 8-week AP® Exam preparation in March-April to hone in key concepts and exam writing skills.

We believe that exposure to real work in a corporate environment allows students to discover their strengths and passion and enables them to determine their college and career choices. We have a growing network of corporate business partners who offer students such exposure through internships or round-the-year work + study programs. These are subject to availability and student interest and fit and include both unpaid as well as paid opportunities.

While the core skills a student must master for a given class are specified by the curriculum curator, how students acquire and hone these skills varies widely based on teachers and students.

At 2Sigma School, we pay close attention to every student’s learning pathway as they engage with our course content, interact in live-classes, and demonstrate understanding of concepts through frequent assessments.

Our data scientists programmatically analyze these patterns and recommend lessons, supplemental topics, prerequisite concepts, and specific assessments to each student based on their unique progress.

Such personalization is impossible without automation. Our education platform is powered by AI-based algorithms to achieve such personalized learning at scale so every student gets the attention they deserve.

Our classes may vary according to the topic of study and needs of students. Most students will engage with bite-sized curated content ahead of class and spend time in active discussions during class with their instructors and a small group of peers.

Our students are constantly assessed on concepts taught, both in class as well as asynchronously. The asynchronous assessments are highly personalized based on past scores to ensure comprehension as well as retention. Instructors review students’ individual performance and decide whether to skip certain topics that students have already mastered, or reinforce prior concepts required to better understand current topics.

Program and Course Details

2Sigma School is accredited by Cognia (formerly AdvancED), a parent organization of the North Central Association Commission on Accreditation and School Improvement (NCA CASI), Northwest Accreditation Commission (NWAC) and the Southern Association of Colleges and Schools Council on Accreditation and School Improvement (SACS CASI). Parents and interested community members can learn more about the Cognia Accreditation at The credit awarded for course completion by 2Sigma School can be provided to your local high school to count towards your graduation and to colleges and universities to support your application.

Most 2Sigma School courses are also NCAA approved and those are listed on the footers of the course description pages. Please do not hesitate to contact us for more information.

Yes. 2Sigma School only offers AP® courses that have been audited by the College Board and approved to use the AP designation.

Colleges have varying policies regarding which AP® courses they offer credits for and what their Exam score minimum requirements are. Please visit the AP Credit Policy Search page for more information.

Once you register for a course, you will be enrolled in the College Board's AP Classroom and will have access to the AP materials made available by the College Board.

In order to receive college credits, you must also appear in the AP Exams conducted by the College Board. Being an online school, we do not conduct AP Exams ourselves. Students registered for an AP class with us (as with other online providers) have to separately register with a local school for the exam. The College Board's website provides links to find local locations.

When you enroll in an AP course with us, your admissions coordinator will work with you to find locations near you where you can take the exam.

For May 2021, the College Board announced Digital Exams that can be taken at home. We will keep our students informed as the College Board updates its exam policies in the future.

We conduct exams periodically throughout the semester and assign letter grades based on our assessment of your mastery in the course. Students will be issued a transcript by the 2Sigma School at the end of their course completion.

Your regular High School may have their own policies on whether they can add transcripts from online course providers to their official transcript. Please check with the 2Sigma School admissions coordinator if we have an agreement with your school in place.

In the event that your school's policies do not allow reflecting your letter grade from online providers in their official transcript, you may still be able to submit two separate transcripts to the colleges you are applying to. Many colleges take both transcripts into account when determining your final High School GPA.

Absolutely! We are here to support your students for one-off needs. Please send an email to your assigned counselor with your student's specific needs. We can arrange 1-1 classes for your student to help catch up on specific concepts or assignments on a needs basis. We do not offer 1-1 tutoring as a standard offering because the quality of content and instructional approach can vary widely depending on the tutor.

At this time we only offer group classes as well as independent study options in our existing, credit-bearing courses. We offer short-term 1-1 classes only as a catch-up option within our standard curriculum. We do not offer a private 1-1 tutoring service outside of our structured curriculum.

Cohorts & Instructors

Our primary goal is to keep students in a cohort that aligns with their needs and preferences of pace, instruction style, and content. This is what allows us to personalize our classes to students.

As students progress through the class, we learn more about them and make minor changes to the cohorts once every few months. These changes to cohorts are designed very carefully to ensure that it works to the students advantage.

We also make minor changes to our cohorts when new students join our classes or existing students decide to take a break.

Yes, parents can express their preferences for having their students being in the same cohort with their friends. We firmly believe that students do their best when they feel emotionally comfortable and safe in a group, and having familiar friends in the cohort only helps. Please let your admissions counselor know and we will try our best to accommodate your request.

If, based on our assessment, we believe that the students preferences for pace, instructional style, content, as well as current proficiency levels are significantly further apart, our admissions counselor will advise parents of their recommendation.

Our instructors are hand-picked primarily from three categories:

  1. Teachers with years of experience teaching AP® courses in our schools (public, private, and charter schools) that are also highly rated by their students for efficacy and passion.

  2. Professionals with years of industry experience in software development and data science with a passion for and prior experience with teaching students.

  3. Graduates from top global universities who have demonstrated specialized skills in related subjects and share a deep passion for education and working with students.

All our instructors go through a rigorous interview process that includes vetting for skills, empathy, and aptitude.

Our instructors are based primarily in the US, Canada, and the European Union. A select few instructors may be based in other countries as well if they are exceptionally qualified with proven credentials and meet the high bar of our US based instructors.

We first match student cohorts and instructors based on their preferences for subjects, grade-levels, and schedules to narrow the range of options. Next, our admissions team uses the results of the initial assessment and student onboarding session to select the instructor based on their personal experience working with other students.

Usually, instructors continue to teach the cohorts assigned to them through the completion of the course. When new students join, existing students graduate, or the pace of student progression requires cohorts to be reformed, instructors may switch the cohorts they are teaching.

Even though we hand-pick some of the best instructors in the country, our programs are designed to provide students with the same quality of education when instructors change. In traditional schools instructors are responsible for every aspect of class, and as a result, have a strong influence on the student's academic experience for the entire year.

A unique aspect of 2Sigma School is that our curriculum and instructional content is curated by some of the best educators globally and is centered on students. While instructors play an irreplaceable role in supporting the students during the class, a significant part of the student's online experience is not dependent on the assigned instructor.

Tuition & Referrals

Referring your friends and colleagues is a great way to express your appreciation for the value 2Sigma School brings to your student. Please visit our Referral Page to generate your unique referral code.

As a thank you for referrals, both your enrolled student and the referred family will receive a $50 tuition credit each once they enroll a student and stay with us for 2 months. The referral credits are per family, so if you refer 4 families, who enroll a student each, you will receive $200 in tuition credits. Due to sibling discounts, the referral credits don't apply to subsequent students from the same family.

We offer a flat 10% off for every sibling you enroll with us.

Say you enroll 2 students within the same family. The first student pays the full tuition and the second one is offered a 10% discount. By default we apply the discount to the sibling who joins second, but you may request the discount to be applied to either sibling's tuition.

We are working on getting approved as a vendor with a number of Public and Charter School Networks. Please search your school network's vendor directory to see if 2Sigma School is already approved as a vendor. You may also reach out to us with specific requests for your Public or Charter School Network at

Requirements & Commitment

Our technology requirements are fairly similar to most live online classes. All our courses require students to be able to run a Zoom Client. The minimum requirement to run a Zoom Client include.

  • A desktop or laptop computer running Windows (PC), Mac OS (Mac), or Chrome OS (Chromebook).
  • A working microphone, speaker, and webcam.
  • A high speed internet connection with at least 10mbps download speed (check your Internet speed).

Students must have a quiet place to study and participate in the class for the duration of the class. Some students may prefer a headset to isolate any background noise and help them focus in class.

Most course lectures and content may be viewed on mobile devices but programming assignments and certain quizzes require a desktop or laptop computer.

Most AP courses are designed to run for a full school calendar year with about 2-3 hours of instructions and 4-6 hours of self-study and homework each week. Students who are taking a full course load during a given academic year will need about 9 months of study to complete an AP course and prepare for AP Exams in May.

We also offer AP courses in Summer when students may have more time to devote to a smaller number of courses and may be able to complete the course in less time.

Yes. While we recommend that students take the AP Exam to get full credit for the course work, it is the student’s decision whether or not to take the exam.

Our program is quite rigorous and is specifically designed to enable students succeed at the course by mastering the concepts well. As a result, we require that students complete module specific assessments and show mastery as they progress through the course.

At this time, we do not allow students to skip assessments and simply listen to our lectures and discussions. If you intend to lightly cover the course content but avoid the rigor of practice problems and assessments expected of AP students, a self-paced online course such as Khan Academy or EdX may be better suited for your needs.

Yes. If you take an AP course during the summer, you are likely to finish the course by Fall or later. However, AP Exams are only administered by the College Board in May, so you must wait until the next May to take an exam. Every student enrolled in an AP course is eligible to participate in our 8-week AP Exam preparation bootcamp that starts in March. So even if you took an AP course during the Summer and finished the course in a few months, you will be able to review the course and prepare for the AP Exam the following May.

Our courses are designed to run for a full school calendar year with about 2-3 hours of instructions and 4-6 hours of self-study and homework each week.

However, individual students will differ in their needs and capabilities and can proceed at a pace that is unique to them. The 2Sigma School welcomes such differences in student’s preferences and allows them to proceed at a pace that works best for them.

If your student needs more time to finish the curriculum, we recommend that they join earlier than the typical start of the school year. Our enrollments are always open and we start new cohorts every couple of weeks, all the way through January.

Yes, some of our introductory courses are well-suited for talented middle school students. See the course requirements tab for each course for details.

Our AP® courses are college-level courses that are intended for High School students.

If your student is really ahead of class and has demonstrated mastery in all the prerequisite courses, they can certainly enroll in an AP® course. Please check the College Board’s policies on your student’s eligibility to take an AP® Exam.

Scheduling & Policies

During enrollment, we ask students for their availability and encourage them to provide as many options as possible. Students then take a pre-admission assessment test to determine their mastery on prerequisite concepts.

We then look for a new or an existing cohort of students that your student can join, while keeping the cohort size between 8-10. Until we find a matching cohort with overlapping availability, your student will start on self-paced learning with email / chat support from instructors. Live classes will begin once the student is assigned a cohort.

It may take a few weeks for your student to join a cohort for live classes, but that should not prevent them from learning using our rich curriculum and email / chat support from instructors.

2Sigma School is open year round except around some key national holidays. These include the day of, and sometimes a day before and after major national holidays. For an up to date holiday calendar, please login to your student’s account.

If for any reason you must permanently reschedule your student’s classes, please notify us at We require at least 2 weeks advance notice for permanently rescheduling your student’s classes.

If the new schedule you requested works for other students in the cohort, we may simply update the cohort’s schedule.

Otherwise, we will look for a new cohort for your student to join. This may take a few weeks - during which your student will continue to learn the curriculum using our rich content and email / text support from our instructors. Students may be assigned a different instructor when they switch cohorts - based on the instructor's schedule. Once a new cohort is assigned, your student will resume live in-person classes.

We understand that students may miss a class or two due to circumstances beyond their control. Our instructors will provide your student with content being covered in class that they can review on their own.

We also encourage students to reach out to their peers in the cohort to assist them with any questions they might have when reviewing such content. Helping and supporting peers is mutually beneficial to all students and is one of the key reasons why our classes are designed around small cohorts of 8-10 students.

If your student needs extra live help from an instructor to keep up with the cohort, we can arrange a makeup 1-1 class with an instructor (possibly a substitute instructor) for a nominal fee. You can schedule makeup classes and pay for them by first logging into your student’s account and then navigating to the parent section that is only accessible to registered caregivers.

One of the unique benefits of an online school is that you can attend classes even when you are traveling.

However, we understand that students may need to miss several classes due to situations beyond their control. If your student has to miss an occasional one or two classes, we recommend staying with the same cohort and using peer and instructor support to keep up. Our instructors will happily provide your student with content covered in class so they can review while they are away and keep up.

If your student must miss several classes and staying with the same cohort is not feasible or practical, let us know and we will find a new cohort for your student when you return. Finding a new cohort may take several weeks during which your student will continue to learn using our rich content and email / chat support from our instructors.

We will give you a 100% refund if you decide within the first 3 classes of our year-long enrollment that our program doesn’t work for your student for any reason.

After 3 classes, we ask that you give us at least 2 weeks notice if you decide to drop the classes for any reason. This allows us to better accommodate other students in the cohort, should the cohort fall short of the minimum 6 students once your student leaves the program.

For our summer of code program, which are quite intensive, we encourage you to attend our FREE workshop if you are unsure whether you want to enroll.

We will gladly refund you a prorated amount if you drop the class at any time during the year. To cancel, simply send us an email at with your request and we will assist you.


Mastery learning emphasizes that students learn prerequisite concepts at a sufficient level of proficiency before new concepts that depend on them.

Let us illustrate this with a simple example from the Middle School Math Curriculum.

Say, in order to learn Ratio Concepts and Ratio Reasoning to Solve Problems (6.RP.A.2 - Grade 6) a student must first achieve proficiency in the following concepts:

  1. Arithmetic operations with whole numbers (4.OA.A.2 - grade 4)
  2. Arithmetic operations with fractions (5.NF.B - grade 5)
  3. Use ratio language to describe relationships (6.RP.A.1 - grade 6)

Some of these concepts are taught in prior grade levels and a 6th grade student is expected to have mastery in.

With Mastery learning, students are tested on the prerequisite concepts (1) - (3) and any gaps in their understanding is reinforced before proceeding with the new concept. This ensures that students learn better and faster. But Mastery learning is hard to practice in large classes because students vary in their backgrounds and their aptitude.

The 2Sigma School’s small classes of 8-10 students are selected based on a placement test to ensure that students in a class are similar in their backgrounds, which allows us to customize the learning pathway better to the students.

Interested in seeing the full graph of concept dependencies for Math and ELA? Checkout

Conventional classes, at public and private schools, as well as all online group classes, publish a fixed curriculum that is designed to run at a pre-set schedule.

As an example, a conventional Pre-Algebra course may cover the following in sequence:

  • Arithmetic Operations
  • Fractions, Decimals, Percents, Ratios
  • Arithmetic Expressions

While the curriculum looks just fine and likely adheres to a State standard, the teaching approach resembles a conveyor belt. It moves along the curriculum regardless of which of these concepts some students already know and which concepts a few of them are not prepared to learn yet because of gaps in their knowledge of the prerequisites. The pace of instruction is set by the schedule even though students may have wide difference in their ability to keep up.

Conventional classes work well for a select few students whose background knowledge and learning pace matches the assumptions and pace of the conveyor belt. Students who are slightly ahead may find it repetitive and boring, whereas those who are behind often feel discouraged.

We draw inspiration from pedagogical research such as the The 2 Sigma Problem that has intrigued educators for 38 years.

Performance of students in a conventional class follows a normal distribution, which in simple terms, means that most students achieve an average level of mastery of the concepts (represented by grade 'B') and less than 5% achieve an A+ level mastery.

We believe that while there are individual differences in students' interest and pace of learning, they are all capable of achieving A+ level of mastery on core subjects. The 2Sigma school's breakthrough approach to learning finally tackles the decades old 2 Sigma Problem and helps students unlock their full potential.

If you are mathematically inclined, you may recall that Sigma (written as σ) is a greek symbol that is used in Statistics to represent standard-deviation of a distribution. In a conventional classroom, the difference in learning between the top few (receiving A+) and the majority (grade B) is 2σ. Our unique learning approach shifts the learning level of students two standard deviations (2σ) to the right.

Graph of Normal Distribution
Have more questions? Check out our top trending questions and answers here.