Results & analysis of marking exercise

Introduction

Firstly a very big THANK YOU to all the teachers who took the time to mark the report and then enter their marks. In total marks from 96 different teachers were added and some of these teachers also added comments. The marks were entered during the month of September 2015 to give teachers experience of marking an Individual Scientific Investigation. One of the aims was to enable teachers to compare their marking with the marks awarded by colleagues from around the world.

Overall total marks

The overall marks given ranged from 13 to 24 out of the maximum of 24. The weighted mean mark was 18.42. The distribution of marks is shown in the following graph.

Caveats

Before giving and analysing the results and commenting upon them it is important to state several key points.

  • This exercise was not an official IB exercise and therefore any marks and conclusions are not in any way recognised or endorsed by the IB.
  • These results only show the marks given by the 96 teachers whose schools subscribe to this website and who responded to the exercise – that was approximately 13% of the total number of chemistry teachers who had full access to this site at that time.
  • Some of the teachers who submitted their marks may have little experience of teaching the IB and little, if any, of examining for the IB.
  • The marks given are based on the teachers’ understanding and interpretation of the information so far available on the Individual Scientific Investigation. This is likely to have been refined now that genuine reports have been assessed and moderated starting with the May 2016 examination session.
  • Although every attempt has been made to submit a piece of genuine work for this exercise that was done by a student and is as close as possible to a real investigation it will not form part of the student’s work submitted to the IB towards his (it was a 'he') Diploma.
  • Although most teachers just submitted their marks, some also made comments. Obviously there is not room to include and discuss them all here but rather than cut them selectively I have copied them verbatim into a separate file so that they are available to all. To help put the comments in perspective I have included the total mark given by the teacher who made the comments, but I have not referred to any individual teacher or school, so all the comments retain their anonymity.
  • Due to the fact that I had more input into this report than would be normal, my own assessment of the work may well show unintentional bias. I should also add that, although I have many years experience as the Principal Examiner for Chemistry Extended Essays, I am not an IB moderator for IA work.
  • Teachers were asked to mark the report as if it was one of their own student's pieces of work, not moderate it, so it contained no annotations. When you send work off for moderation it is helpful to the moderator if you show how you arrived at your marks for each criterion by annotating the work.

    and finally
  • There is no "right" answer. The reason for moderation is to adjust the teacher's marking so that it is in line with the marks awarded by the Principal Examiner for Chemistry Internal Assessment, not to determine whether the teacher's marking is right or wrong.

Detailed results and analysis of the exercise

When analysing the results it is worth bearing in mind one new directive from the IB, which came out while this exercise was in progress. On 18th September 2015, Catrin Brown, who is one of the official moderators for the IB discussion forum on the OCC[1], wrote,

As stated in the Guide, the report should be limited to around 6-12 pages, without automatic penalties for a report that is slightly longer, as long as the report remains relevant and concise. The Communication statement:" The report is relevant and concise thereby facilitating a ready understanding of the focus, process and outcomes of the investigation",
is more likely to be met by a report of about this length. A sensible stance in relation to presentation with regard to font size and margin width should be held, to ensure that good communication skills are demonstrated. In the same way, graphs should not be reduced to such a size that they become uninformative, simply to stay within the page limit.
Candidates should not add on appendices in addition to a write up of about 12 pages and should not send in excessive quantities of raw data from data loggers (although showing an example of how raw data have been processed will be helpful to the moderator). Reams of extra work should not be submitted; teachers marking the work should annotate it if they judge the processed results to be a true reflection of the raw data from, for example, a data logger. Full calculations are not expected to be shown, examples will suffice and a worked example from a calculation carried out on a spread sheet or a programmable calculator will not be expected.”

There are many aspects that can be examined. Firstly, the range of marks varies from 13/24 to 24/24, that is, from 54% to 100%. The component grade boundaries have not yet been set but this may equate to a range of Grade 4 to Grade 7. The mean mark of 18.4/24 is likely to be very close to the 6/7 boundary[2].

Secondly, before looking at the individual criteria it may be worth addressing two points raised in the feedback comments.

6-12 pages: Some teachers asked if it must be double-spaced. The directive at the moment is that if moderated work is to be e-marked then it is requested that it is double-spaced but it is not mandatory. This means that the IB needs to clarify what 6-12 pages means if it is double-spaced. As I understand it at the moment, the first submission of moderated work for May 2016 will be electronic not hard copy.  There is currently no penalty for exceeding 12 pages as long as the report remains “relevant and concise”.

SL or HL: One teacher in his or her comments wondered whether the report was by an SL or by an HL student. It was in fact HL but this should be irrelevant as they are marked according to the same set of standards irrespective of the level.

Specific criteria

Personal engagement

This is where there was the closest agreement from everyone. Almost all teachers awarded 2/2 with just a few awarding 1/2. No one gave 0/2. The mean grade was 1.9/2. Those that commented generally stated that there was evidence of personal engagement throughout. I totally agree with this and awarded the maximum mark for this criterion.

Exploration

The marks given ranged from between 3 and 6 out of 6 with a mean mark of 4.6. Probably the most contentious issue that falls under this criterion is whether or not the Research Question is fully focussed. As it is phrased it is really a ‘yes’ or ‘no’ question and the student already knows the answer from the cookery book. The student does flesh it out later but my advice would be to encourage your students to be as specific as possible in the wording of the Research Question itself. They could include the method they are going to use to determine the amount and also specify that the percentages are percentages by mass (rather than just ‘percentages’). Some teachers commented that the section on the safety procedures was rather superficial. None of the chemicals or the method used are particularly hazardous. I think it would be unfair to penalise the student for what they have written on this as they did show an awareness of safety and students who ‘do not get their hands dirty’ in the lab, i.e. do no practical work, do not have to include this anyway. I would award 5/6 for this criterion.

Analysis

The marks given ranged from 2 to 6 out of 6, although only one teacher awarded 2/6. The mean mark was 4.2. Some of the comments made by teachers underline the importance of reading the report carefully. On first reading it looks like the student has worked out the hydrogen ion concentration and not realised that oxalic acid is diprotic. More careful reading shows that the calculation has been performed correctly when the student lists the oxalic acid concentration in the table on page 8 where he then assumes that all the acid found from the titration was due to oxalic acid. Similarly one teacher made the comment that the sodium hydroxide solution used in the titration had not been standardised and yet the student clearly states on page 4 after standardising the sodium hydroxide solution with oxalic acid of known concentration, “The method was found to be accurate to within 1% of the expected result, which means that I could assume the technician made up the sodium hydroxide solution accurately”. Some commented that the tables had no headings. This is true but should probably be addressed when considering communication. There were comments too that the no uncertainties were listed in the raw data tables. This again is true but they were given immediately afterwards so they were present in the report and therefore in my view this should not be penalised. I awarded 5/6 for this criterion.

Evaluation

Here again the marks ranged from 2 out of 6 to 6 out of 6 with a mean mark of 4.5. Again only one teacher gave a mark of 2/6 but it was a different teacher than the one who gave 2/6 for Analysis. To gain 6/6 for evaluation a student has to:

  • Present a detailed conclusion that is consistent with the facts presented and is completely relevant to the research question.
  • Justify the conclusion by relevant comparison to the accepted scientific context.
  • Discuss the strengths and weaknesses of the investigation and the methodology used. This should include limitations associated with the data and sources of error and show a clear understanding of the factors affecting the validity of the conclusion.
  • Discuss relevant and realistic ways in which the investigation might be improved and extended.

I actually think this was a good evaluation considering the time constraints. One teacher commented that they should have done more trials but this was simply not possible within the ten-hour limit. Others thought that more attention should have been given to calculating and propagating uncertainties. The student stated clearly the importance of the underlying assumptions and realised that they are far more relevant than minor uncertainties. Perhaps the difference between systematic and random errors should be stated, as one teacher wrote, but do real scientific reports really do this? Similarly, he compared his result with the literature value and stated clearly on page 10 why he had not done the percentage error calculation that one teacher would have like to have seen (“Because the literature values are given as a range it is not particularly helpful to calculate the percentage errors.”). Several teachers commented that the suggestions for extending the investigation were strong. I awarded the full 6/6 for evaluation.

Communication

The marks ranged from 1 to 4 out of 4. Only one teacher gave 1/4 with most giving 3 or 4 out 4 so that the mean mark was 3.2. One teacher commented that more sources should have been quoted and yet in an investigation lasting a total of ten hours the students really will not have time to do a really thorough background research. Personally, I think for this investigation the five that were listed in the correct format on the last page were perfectly adequate. It is perhaps nit-picking as the tables given were described in the text above them but think that the tables should have been given proper headings and perhaps numerically numbered as well so for this reason I awarded 3/4 as I thought that, other than that, the communication was good.

Closing comments

What follows is just my own personal view.

I think the fact that such a range of marks (from 13-24) was given by a sizeable number of teachers from many different countries suggests that the problems that the IB has faced in the past over the IA are not going to magically disappear next May. By attaching all the comments and marks I have tried to share as best as I can with you the views of your colleagues. There is clearly a wide difference of opinion as to how many of the criteria should be interpreted. Whilst this exercise is interesting and, I hope of real value, it cannot claim to provide clear and unequivocal guidance. What matters is that you are consistent in your marking and that you apply common sense regarding what is possible within the ten-hour time frame. I think the student himself commented twice (pages 1 and 10) on the restrictions that the time limit caused. Teachers need to discard some of the minutiae that were focussed on in the old criteria and realise that the new IA requires a more holistic report. You should mark positively for what is there rather than negatively for what is missing. My 'gut' feeling is that this work is of Grade 7 quality and, given all the restrictions that ten hours imposes on such an investigation, deserves the 21/24 I awarded.

Download the full comments made by teachers

Footnotes

  1. ^ The OCC was replaced by My IB in 2017
  2. ^ In fact the boundaries have now been set so that grade 6 covers marks from 17-19 and Grade 7 20 - 24.
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