Reflections from examining 2018

This season I marked 140 IB DP Biology HL Paper 2 Timezone 1 papers. It was unusual for a couple of reasons: 1) I managed to pass the qualification marking on the first attempt for the first time in six years! 2) I managed to complete my marking target within seven working days and nine days before the deadline – the first time I have managed to complete the work so quickly.

I felt that this years timezone 1 exam was very straightforward to mark. This was particularly evident in the data analysis responses where the mark scheme was much easier to interpret than I recall previous years being.

Qualification

To qualify for marking, normally there are practice scripts and qualifying scripts to mark. The practice scripts are a chance for you to view comments from the senior examining team, so when undertaking these it pays to go very slowly, really thinking about how the mark scheme applies in each question and when you have marked each question, checking your own marking against the comments by toggling on the annotations. Using this method you may become quickly aware of any small details in the comments that you have missed.

In the past when I have undertaken the qualifying scripts I have opted to mark them in bulk and then submit them in bulk, so I would only submit the scripts once I had marked all of the papers. This year, instead, I submitted each script after I had marked it. This gave me the advantage of being able to read the annotations on each of the qualifying scripts, check my tolerance and adjust my marking of each of the subsequent qualifying scripts. I think this may have been a primary reason why I qualified first time.

Student misconceptions on the paper

I marked 140 scripts and when you mark that many certain themes begin to emerge. This year worryingly a large proportion of candidates were conflating the mechanisms of global warming with holes in the ozone layer. This is not a new thing and it is a problem that I have noticed in previous years but this year the sheer number of candidates writing a confused response to the question on the mechanisms of global warming was staggeringly impressive.

In 2018, 18-year-old students are still writing that carbon dioxide creates holes in the ozone layer and this is what heats up the planet – or something similar. This needs to be addressed. A teacher or teachers somewhere must be teaching kids about the ozone layer.

Now I struggle to believe that this is the result of their biology teachers (who most likely will have studied this subject to sime depth and understand the science) and I am wondering if this is the result of colleagues in other subjects unrelated to science. We know that there is a lot of confusion about climate change in the media and that the scienitific debate is often misconstrued in the popular press. We also know that this is an issue of global importance and for that reason, other subject teachers may well address it. IB student could meet it in TOK, studies in language as well as geography and other teachers. I am wondering if there are some miseducated teachers out there who are confused on the issues of climate science and are confusing their kids. This would be a great area for practitioner research and opens up the question about the professional responsibilities of teachers who have a particular subject specialism: should teachers who are well educated on a particular topic be responsible for sharing that knowledge with colleagues who may also approach this topic in the own teaching?

(on a side note a colleague previously told me that XX and XY chromosomes were “a lie” in a discussion on LGBTQ+ issues in school).

Other misconceptions that became apparent were:

  • Candidates thought that water was an organic molecule
  • Candidates didn’t understand that DNA transcription/translation = protein synthesis = gene expression = expression in the phenotype.
  • Not understanding that linked loci are genes on the same chromosome not in the same place.

Common factual errors were:

  • Few candidates knew that glutamic acid is replaced by valine.

Please share your thoughts..

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