Internal Assessment


In the past the term 'Internal Assessment' was applied to the whole 40 hours (SL) or 60 hours (HL) practical programme. Now it very specifically only applies to the Individual Scientific Investigation. The Individual Scientific Investigation is scheduled to take ten hours of the Practical Scheme of Work and is the ONLY part that forms the 20% of the final internal assessment component mark. There will be a few marks devoted to the type of skills and understanding covered in the mandatory laboratory components in Section A of Paper 3 in the external examination (see  Experimental work questions for practice examples)  but none of the practical work counts towards the internal assessment mark apart from the Individual Scientific Investigation. The great strength of this is that it enables teachers to plan their own practical programme as an integral part of their 150 hours (SL) or 240 Hours (HL) teaching course without having to worry too much about assessment. It means that students can learn through practical work and reinforce their understanding and they do not have to write up each and every practical to an agreed set of criteria. The downside is that all the 20% of the internal assessment marks are placed on just one single 10 hour investigation. This means that many teachers will use the practical programme to 'Scaffold' the Individual Scientific investigation, i.e. to teach students the skills necessary for them to achieve a high mark in their individual investigation.

What is the Individual Scientific Investigation?

The point of internal assessment is that it allows students to demonstrate they can apply their skills and knowledge, and at the same time can pursue their personal interests, without the exact time limitations and other constraints associated with the written examinations. The internal assessment task consists of just one scientific investigation which should take about ten hours and be presented for assessment in a 6-12 page write-up. The investigation should be complex and commensurate with the level of the course although Standard Level and Higher Level students will be marked according to the same set of criteria. It should have a purposeful research question together with the underlying scientific rationale for it. Although the investigation can follow a traditional hands-on approach there is much more scope that can be used and, in fact, it is permissible that all the data employed can be obtained from secondary sources. This is perhaps to accommodate the fact that in the near future students will be able to do an online IB Diploma chemistry course where traditional supervised practical work will no longer be possible. The IB lists some of the possible tasks that could be used. These include:

• a laboratory investigation using a hands-on approach.

• analysis and/or modelling using spreadsheets.

• using a database to extract information leading to graphical analysis.

• a hybrid of the above three, i.e. using a spreadsheet or database together with a more traditional hands-on investigation

• the use of an interactive and open-ended simulation.

Note that some of the tasks could consist of appropriate and relevant qualitative chemistry that is also combined with quantitative chemistry.

The Individual Scientific Investigation is marked out of 24 according to five different criteria: personal engagement, exploration, analysis, evaluation and communication. These do not all have equal weighting. Exploration, analysis and evaluation are each worth a maximum of six marks, personal engagement is marked out of two and the maximum mark for communication is four. Once the total mark out of 24 is obtained it will be scaled to a mark out of 20 which will make up the internal assessment component mark. Samples of student work from each school will be moderated to try to ensure a consistent standard.

Almost all students will carry out their Individual Scientific Investigation during the second year of their two-year course. I have attached links (on the left) to attempt to break down the whole process into manageable sections to help your students achieve to their maximum potential. This includes preparing students beforehand, choosing the research topic and the production, assessment, internal standardization and moderation of the Individual Scientific Investigation. There is also an IA example & marking exercise  for you to practise your marking and to see how your marks compare with those given by other IB teachers from around the world.

All materials on this website are for the exclusive use of teachers and students at subscribing schools for the period of their subscription. Any unauthorised copying or posting of materials on other websites is an infringement of our copyright and could result in your account being blocked and legal action being taken against you.

Comments 21

SHALINI SHARMA 25 May 2017 - 05:33

Dear friends

Please give your frank opinion/feedback on the following topics-

1. To what extent does temperature affect the quality of nitrogenous fertilizer in terms of nitrogen content?' - This idea comes from one of my students. Actually there are weather extremes in our country during the same months. His idea is to keep the soil at different temperatures with the fertilizer for a fixed period of time and then compare the initial and final N2 content using the standard kjehldahl method. I am not very sure but I found the idea quite fascinating,

2. Another student of mine wants to test the change in optical activity of a racemic mixture with temperature, if any.

3. Third candidate wants to check the amount of eucalyptol (she will be using steam distillation) in common products and wishes to check it with the permissible limit as exceeding a certain amount, eucalyptol can be harmful to the body.

4. The fourth candidate wishes to test the effect of electrolytes (mostly chlorides) on the rate of rusting. However, an identical approach has been taken by one of my old students, which this student is not aware of. Is it permitted that two candidates take the same approach? Would the candidate be penalized?

5.Another wants to test quality of fuel prepared by different ratios of kerosene and alcohol (ethanol) in terms of enthalpy of combustion.

6. Another one wishes to test the quality of oils on re-heating the oil (as people in our country use the same oil many a times) by calculating the iodine number before and after.

7. Last candidate wishes to carry out a common lab -studying the rate/ or enthalpy of esterification reaction on changing the alcohol.

Awaiting your invaluable, frank opinion, please. Please let me know if you need any further details.

Thanks for your time.


SHALINI SHARMA 25 May 2017 - 06:06

By the way the above are proposed EE topics.

SHALINI SHARMA 25 May 2017 - 07:07

I need an opinion on the IA. One of my students carried out a lab on rusting . Now this naturally went beyond 10 hours but I did not downgrade it as the 'watch and wait' period for rust to happen was a period on inactivity for the student. Am I right?

Also please if somebody could elaborate the correct procedures for making solutions- say 0.1 M NaOH and 0.1 M H2SO4.

Thanks again

Geoffrey Neuss 25 May 2017 - 17:30

Shalini, See Maria's answers to your question on EEs that you also put on the OCC. There are many websites that explain how to make up analytical chemical solutions e.g. see /. For 0.100 mol dm-3 NaOH and 0.0100 mol dm-3 H2SO4, if you can, it is best to get a pre-prepared ampule. Once broken the contents can simply be dissolved in distilled water and transferred with all the washings into a volumetric flask and then the total volume made up to the mark followed by shaking to ensure it is throroughly mixed.

SHALINI SHARMA 26 May 2017 - 04:38

Thanks Geoffrey. I read Maria's so meaningful and apt comments.

SHALINI SHARMA 21 September 2017 - 11:20

Dear Geoffrey,
Hope things are fine at your end.
I need your help with one question- How to calculate enthalpy of combustion of mixtures? I referred many sites but none talks of mixture. One of the teachers told that find the enthalpy change for each component separately and simply add up the two. It does not sound correct to me as the IM forces would change on mixing two soluble liquids, thereby affecting the final enthalpy?
Please help.

Geoffrey Neuss 21 September 2017 - 11:54

Hi Shalini,
It seems to me that this in itself could be a great area to explore for an IA. The enthalpies of combustion of the pure components can easily be found in the literature. Then assuming complete miscibility the student could find the values experimentally for both the pure components and known different mixtures of the two and see whether the relevant delta H values can simply be added together or whether internal molecular forces between them does affect the total enthalpy change. I suspect it depends to some extent on the components e.g. I would expect methanol and ethanol to be additive as the attractive forces are similar but what a great area to research within a school laboratory.

Darren Hornell 8 November 2017 - 03:07

Hi Geoff

I have a student who has elected to do the length of carbon chain on rate of oxidation and they have got a trend that says that as the length of carbon chain increases the rate increases. I have been looking for information on why as they are stuck and haven't found anything on it, do you have an idea about why?

Geoffrey Neuss 8 November 2017 - 14:23

Hi Darren, I think I need much more information. What class of compounds are you referring to that are being oxidized, what is the oxidizing agent, what is the product, what are the conditions under which the oxidation is taking place (solvent, temperature etc.) and how is the rate being measured?

Darren Hornell 9 November 2017 - 00:49

He did primary alcohols in acidified potassium dichromate at aldehydes were the products, 50oC. rate was measured as an end point colour change.

Geoffrey Neuss 9 November 2017 - 09:19

Darren, It does seem a rather unlikely result (the rate of the reaction to produce hydrogen when sodium is added to primary alcohols definitely decreases as the chain length increases). I think the method used needs checking carefully. For example was it done in an open system? If ethanol, propan-1-ol and butan-1-ol were used then both ethanal and propanal boil below 50 oC so may have escaped before any further oxidation could occur whereas butanal has a boiling point of about 75 oC . It might also be worth checking which was in excess, the alcohol or the dichromate, as the dichromate should very definitely be the limiting reagent if you want to compare the rates to form the aldehyde. I wonder what happens if you put equimolar amounts of each alcohol in a closed system with the same amount of acidified dichromate and simply leave them to react at room temperature?

Khalida Qureshi 22 December 2017 - 03:00

Hello Geoffrey ,
One of my student wants to conduct an IA on this (i) find the rate of reaction by observing the rate of fermentation of yeast with glucose, fructose, sucrose and lactose. He plans to carry out his experiment by meausing the amount of CO2 evolved for each type of sugar.

Kindly suggest

Geoffrey Neuss 22 December 2017 - 05:48

Hello Khalida, It should not pose any particular practical problems to carry out but your student will need a clear research question.

Khalida Qureshi 22 December 2017 - 07:21

Thanks Geoffrey

Samia El Hajj 21 January 2018 - 07:39

I started teaching IB last year and I just wanted to ask about the IA format. If the student used the MLA and wrote his IA without spacing in order to fit in 12 pages, is it ok? and should the citations at the end be a part of the 12 pages? My student wrote her IA in 12 pages and her citation took 2 extra pages, is it OK?
Thank you for any help

Geoffrey Neuss 21 January 2018 - 09:05

Hello Samia, I suggest you look at “Frequently asked questions” which is available from the IB under ‘resources’ on My IB as it details what is required for the IA. The IA does not have to be double-line spaced and candidates will not be penalized if it is not double-line spaced. The 12 pages includes the bibliography. I am slightly surprised that your student has a bibliography that takes up two pages (most EEs are less than this and the whole IA is only ten hours work).

Samia El Hajj 21 January 2018 - 12:43

I will look again at MY IB. Thank you so much for your reply.

Marc Curran 23 January 2018 - 03:45

Dear Geoffrey, Could you please clarify a few questions I have?

I have been told that no two students can do the same or similar IA, is this correct.

The IA can not be something that is proving a law/relationship that is already known. Does that mean that students can not carry out more classical investigations like: enthalphy of combustion of different alcohols and temperature/concentration based rates of reactions?

The investigations that many of the students are trying to carry out are increasingly complex and to make them unique and very specific, which is making finding secondary data to support their work increasingly difficult to find.

Hope you can help.

Geoffrey Neuss 23 January 2018 - 12:48

Hi Marc, As far as I am aware the IB makes no reference to identical or similar topics but it makes no sense to have two students from the same school with the same RQ as you will never be able to know absolutely that there is no collusion. Similar topics is a bit more difficult. What is important is that you can vouch that their IA is ALL their own work.
I thought it was Popper, not the IB, who first said that you cannot do an experiment to prove a scientific law (NOS/TOK)! There is nothing wrong with carrying out classical investigations, e.g. on enthalpy of combustion etc., but rather than have a RQ which is essentially 'Does it do/contain what it says on the tin?’ get the students to come up with an original problem that uses the classical technique(s). As to your last point – it is only ten hours work so keep it relatively simple.

Radwa Hussein 1 February 2018 - 14:28

Hi Geoff,

I wanted to check with you about the expectations for the IA regarding SL and HL students. I always encourage my HL students to incorporate HL concepts/calculations when possible. However, that it not always feasible. What do you think about that?

Paul Lloyd 2 February 2018 - 20:09

Hi Radwa
Geoff is away in the Himalayas, beyond wifi for a while. I'm a friend of Geoff's and an IB Chemistry workshop leader, helping out on the website while he's away. I agree - I think it is important to ensure that the level of an IA investigation is 'commensurate with the level of the course', so HL students should indeed incorporate HL concepts whenever possible/appropriate.
Paul Lloyd

To post comments you need to log in. If it is your first time you will need to subscribe.