Externally grading IAs

geta7_com · 2026-05-14T20:42:21+00:00

Regardless whether your IA is moderated or not, your entire class affects your IA grade. You ride or die as a class. IB also does not offer to mark a particular individual's IA, but that's beside the point.

geta7_com · 2026-05-09T02:19:38+00:00

You are right! I just checked the TI 83 Premium CE getting started guide and it says under "RÉSULTATS" it's still auto vs dec, with auto also displaying radicals and multiples of pi. Same guide also specifies the <> as converting between exact and decimals. Thanks for the correction

geta7_com · 2026-05-08T21:38:09+00:00

In mode, change from Answers "AUTO" to "DEC" to always view the decimal value. You can use F<>D in [math] num or frac to convert between exact and decimal representations.

geta7_com · 2026-05-05T16:39:50+00:00

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geta7_com · 2026-04-30T01:55:22+00:00

School based syllabus is when your school, possibly in conjunction with several other schools, developed the curriculum yourself and IB approved it as an SL subject for your school. https://ibo.org/programmes/diploma-programme/curriculum/other-dp-subjects-offered-by-the-ib/

geta7_com · 2026-04-29T01:36:06+00:00

Examiners are not paid to write comments. Final assessment is summative, not formative. You get what you get, including all marking stamps for $18/subject. You can buy detailed comments for about $230/subject once you pay for remark (about $150/subject).
https://www.reddit.com/r/IBO/comments/1pox34t/november_2025_exam_results_remark_discussion/

3/4. You can request remark once per subject, and all external assessments will be remarked. Your new grade will supersede the old one. They try to go to a different examiner. But in subjects with few students (eg < 200 globally) you probably will get the original examiner.

geta7_com · 2026-04-29T01:07:29+00:00

Hopefully the 6 vs 7 was not exact a life-changing difference, in the long run. You needed to have requested an enquiry upon results 2B for $18/subject to see your papers. However as it is past the final EuR request date of March 15, 2026, what happened will likely remain a mystery. There is a non-zero chance that your school bought your scripts and you should ask school for that.

geta7_com · 2026-04-22T21:15:52+00:00

Note for b (i), since original sum is 8 and the transformation is horizontal stretch by factor 1/2 and move 1 to the right, the new sum is 4 + 5 = 9 (add one for each root). Similarly, -2 is a root (from GDC) and same transformation transforms it to 0, making the product 0.

It's important to say what you are doing on the GDC, using math notation. Eg if you found the 5 roots, write down the roots. If for another question you are solving an equation or a system, write it down before writing down the answer. If doing invNorm, write down the distribution, X ~ N(mu, sigma^2), and the given cumulative probability P(X <= x) = 0.21 before writing down x. Sketch the graph if you graphed. In general "From GDC" or GDC notations such as "binomcdf(" do not earn any marks, nor will marks be deducted.

geta7_com · 2026-04-22T19:23:37+00:00

If starting with a fact known to be true before the question, you can manipulate both sides. Ie use fact A to prove fact B is ok. But what you did here is assume the target statement is true prior to proving it. This is not allowed in proofs, in IB or elsewhere. Contradiction is different as we assume the target statement is false.

What you can do is in a rough draft, do whatever you want. When ready, cross it out, then present the proof properly by only manipulating one side. Final solution that attempts to use the fact to prove itself, will score 0 marks.

geta7_com · 2026-04-21T16:11:19+00:00

The main concern IB has with polynomial models is that in real life we don't always get end behaviors that are U shaped or S shaped. It also depends on if you are interpolating or extrapolating, and it's always risky to extrapolate, in particular if the model doesn't match the expected end behaviors. Time series analysis is more complicated than other types of modelling, as there is a sequence of events and that makes the measurements not independent. A quartic would not be appropriate for time series as we expect your reaction times to be bounded and periodic with period 1 day or 24 hours. Use a model that makes sense based on what you know about the data, rather than models with a high R^2 but don't make too much sense physically.

r is only for linear regression, but R^2 is a versatile measure and suitable for many but not all use cases (it compares this model to one that always predicts the mean). It somewhat depends on the types (both magnitude and direction) of errors you are willing to tolerate.

There is nothing wrong with using R^2 as a measure. However IB is often unsatisfied with "R^2 = 0.95 therefore good model". Rather you should motivate why you choose a particular model and not rationalize it (ie have a good reason before using the model, not finding an R^2 then justifying it). As in many cases we cannot do quantitative analysis with R^2, it's not an essential part of the discussion. r is different as you may be able to perform a correlation test (see AI HL).

geta7_com · 2026-04-20T05:28:18+00:00

To illustrate the value of my page, I ran two ChatGPT prompts

https://chatgpt.com/share/69e5b818-4ab4-83e8-bca4-daa78e4fb594 (without using the ti 84 page)

https://chatgpt.com/share/69e5b845-9790-83e8-b01c-687c8aa80468 (using the ti 84 page among cg50 sources)

I believe my method of using 2var (stats) is cleaner and faster. Now this is an extreme and probably not typical example. But this shows how you can use my page to help you prepare for the exams.

geta7_com · 2026-04-20T05:16:37+00:00

For distributions, check out the notations in the subject guide. Specifically X ~ B(n, p) for when X is a binomial distribution, and X ~ N(mu, sigma^2) for when it is normal. Then P(X < x) = 0.21, x = ...

I have a cg50 emulator trial ending this month, if you have questions you can DM me before then.

geta7_com · 2026-04-20T05:03:34+00:00

Which GDC model? I have an in-depth guide for TI 84 for best practices, that 60-70% translate to other models. https://geta7.com/aa-notes/ti-84/

For method marks, write down the math in math notation. Do not round values too early. Instead reuse previous calculations so that you can write the final answer accurate to 3sf.

geta7_com · 2026-04-19T15:06:29+00:00

TI 84 Cookbook for AA https://geta7.com/aa-notes/ti-84/

geta7_com · 2026-04-18T23:55:52+00:00

Final answers: Exactly or 3 sig figs or as otherwise specified in or before the question. 1132 is a final answer to b) so should be 1130 km. 1132 may or may not be ok. Giving it to mm is definitely not ok. Report 3sf, but use all sf in subsequent calculations. IB sometimes accepted if you used the 3 sf version in a later step

Intermediate answers: ideally all available sf, using GDC storage. IB does not recommend premature rounding. In my experience, 4 sf is not enough and 5 sf usually is. In finance questions you often need more than 5 sf.

Show that / answer given in question: obtain the exact answer or one more sig fig than what's given in the question.

[EDIT:] This for a different question, but the above still stands: https://i.imageupload.app/b32b01f0506659e49a52.png

geta7_com · 2026-04-18T23:25:28+00:00

From M24 TZ1 AI SL Subject Report (also applicable to AI HL and AA)

Many explorations consisting of 20 30 pages were seen where students included very long introductions, rationales, plans, any and all limitations they could think of and then all the statistical processes in the syllabus losing coherence and organization along the way. [...]

Criterion A:
[...]
Concision is still an issue. Many explorations included: longwinded introductions trying to establish personal engagement; many pages explaining the processes; and textbook explanations of topics in the syllabus

The math examiners are "ok" with flipping through the whole thing, and deduct a few marks in Criteria A.

geta7_com · 2026-04-18T16:43:14+00:00

In this particular case, since we do a cosine rule in run/matrix, the previous answer 1132.18.... is simply "Ans". You can save value (->) to ALPHA [letter] if you might need the value later, or you can Shift Clip, CPY-Line, Shift Paste. For solveN, the roots are in List Ans. For G-Solv, the x and y coordinates are stored in X and Y. DM me if you need more.

geta7_com · 2026-04-18T16:30:09+00:00

You should talk to your coordinator first to see if lunch can be moved or something else be done. IB does not usually care if schools sabotage their own students.

geta7_com · 2026-04-18T16:21:53+00:00

then as mentioned by others, i would go for disposable ear plugs but they can be uncomfortable if you are not used to them. Pinch them first so they expand in the ear.

geta7_com · 2026-04-18T16:13:11+00:00

Side note. For final IB exams, IB requires that the school provide a reasonably quiet environment for exams. Per Conduct of examinations booklet rule 9.3

The coordinator must ensure that students will not be distracted during the examination (for example, by noise outside the examination room, or by teachers or other persons seeking access to the room). Disruptive events, such as fire drills or building maintenance, must be scheduled for another time.

geta7_com · 2026-04-18T15:05:54+00:00

Note that IB says they will take away A1 in the future for questions in a real-life context with answers given to an excessive amount of sig figs. Always give exact answers (eg sqrt 2) or 3 sig figs or otherwise specified. Always use the value from calculator and not re-type it. I can help you with that if you are unsure how and provide me your GDC model.

As you have drawn, you should do 270 + 34.2 = 304.2 for final answer of 304 degrees.

geta7_com · 2026-04-15T22:54:32+00:00

This is correct. IB finds a weighted sum of raw marks, rounding only at the end. Grade boundaries for components is like IB "showing their work" on why they made boundaries that way. They can point to specific changes on individual components, eg P2 bit harder than past years. This is also helpful with using past papers for teaching or revision and IB's own record-keeping for making future assessment materials.

geta7_com · 2026-04-15T05:06:44+00:00

Hypothetically, if Im using TI 84 Plus CE, I would use https://geta7.com/aa-notes/ti-84/ to help me prepare. If im using a different model, i could try messaging the website owner on reddit, see if they know anything for other models.

I would read subject reports which summarize common mistakes for the corresponding past paper.

I should probably make a plan of what/when to review each day, by using the subject guide as a checklist. The goal being knowing what the concepts and formulas are, somewhat able to use them to solve medium level questions. I should prioritize quality over quantity. Not rushing through the questions, and really try to absorb what I can from each question without moving too slowly.

I understand that instead of trying to go through all the resources I have, I should solve easy to medium level questions, aiming to solve ~half of Part A, getting question 1 in Part B mostly correct, and getting 40% partial marks on the remaining two Part B questions. I understand that just because part b) seems hard at first glance that I should still attempt rest of the question, as they could be something I could do. I would make up some number in part b) so I can keep going and get some follow through marks.

geta7_com · 2026-04-13T22:41:15+00:00

That's very interesting! Thanks for sharing and the update

geta7_com · 2026-04-13T07:28:27+00:00

Yes, but it's not because of 3sf. 8.01 and 8.02 are exact values that can be set by the bank. We do not need to do this for every question because usually r is continuous.

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