Mr Baumgarten

Computer Science teacher and self confessed geek

Case study (HL)

The case study forms the entire basis of Paper 3 of the IB External Exams for Computer Science. The case study is released in May for the following years examinations.

Paper 3 is out of 30 marks. There are always 4 questions. Question 4 is an extended response worth 12 marks (40%) of the paper.

As part of your IB preparations, ISL students will have a paper 3 exam in their Year 13 mocks.

Goals of the case study

Through their investigation of the case study, students should be able to:

  • demonstrate an understanding of the computer science concepts fundamental to the system(s) in the case study (objective 1)
  • demonstrate an understanding of how the system(s) in the case study work (objective 1)
  • apply material from the course syllabus in the context of the case study (objective 2)
  • explain how scenarios specified in the case study may be related to other similar local and global scenarios (objective 3)
  • discuss the social impacts and ethical issues relevant to the case study (objective 3)
  • explain technical issues relating to the case study (objective 3)
  • evaluate information that may be gathered from local and global sources including field trips, interviews, primary and secondary research, invited guest speakers and online interviews (objective 3)
  • evaluate, formulate or justify strategic solutions based on the synthesis of information from the case study itself, additional research and new stimulus material provided in the examination paper (objective 3).

I am always open to the idea of a field trip or a guest speaker visitng our class if it is relevant to the case study. It would be great if you can refer to some primary research in your answers (the time I visited the....). Let me know if you have any suggestions.

Structure of paper 3

  • 30 marks, 60 minutes, worth 20% of your final CS grade.
  • 3 x Short answer questions worth ~6 marks ~12 minutes each
    • Command terms: Define (2m), Outline (2m), Explain (4m), Describe (4m)
    • Terminology is very important for questions 1, 2 & 3. This includes the list the IB provides at the end of the case study, and some other terms scattered from the case study that don't make it onto the list. Students needs to not just know the definition of these terms but be able to describe what they are.
  • 1 x Extended answer question worth 12 marks 24 minutes.
    • Command terms: Compare, evaluate, discuss, to what extent
    • Carefully study the five challenged list at the end of the case study - one of these will form the backbone of the extended response question 4.

Class time schedule

  • Prior - Pre read the case study. Highlight & make notes on key points. Prepare definitions for all terminology words (those provided and those additional ones identified). Bring a list of questions with you.
  • Week 1 - Together discuss the case study, pick it apart. Discuss key points and questions identified. Terminology formative test in the style of questions 1/2/3.
  • Week 2, 3, 4 - Research and write papers on the challenges as assigned (questions will be provided by the teacher)
  • Week 5 - Review papers written by peers on various challenges, making personal notes on each. (have students use two different coloured highlighters to identify where their peers have provided (a) new research based information that was not provided in the case study and (b) contrasting of perspectives)
  • End of unit - Complete a full practice paper 3

Question 4

  • There will always be one extended response question in paper 3. The command term used will be from the list of verbs in objective 3: Construct, analyse, evaluate, formulate, to what extent.
  • You will not get passing marks if they don't reveal independent research within your response. If the content of the response contains nothing new that can't be gleaned from just reading the case study itself, it will not pass that question.
  • Your response MUST include an analysis from multiple perspectives (eg: for/against) EVEN IF THE QUESTION DOES NOT EXPLICITLY REQUEST. This is because while the question may change year-on-year, the mark scheme is fixed, and the IB definitions of analysis require multiple perspectives. You must also, after having analysed multiple perspectives, reach a conclusion or recommendation. I had a student a couple of years back who had his papers returned to me for review and it was clear from the marker comments that he was marked down for these reasons so it is not something I really push with my students.

Question 4 mark scheme

No marks

  • No knowledge or understanding of the relevant issues and concepts.
  • No use of appropriate terminology.

1-3 marks - Basic

  • Minimal knowledge and understanding of the relevant issues or concepts
  • Minimal use of appropriate terminology.
  • The answer may be little more than a list.
  • No reference is made to the information in the case study or independent research.

4-6 marks - Adequate

  • A descriptive response with limited knowledge and/or understanding of the relevant issues or concepts.
  • A limited use of appropriate terminology.
  • There is limited evidence of analysis.
  • There is evidence that limited research has been undertaken.

7-9 marks - Competent

  • A response with knowledge and understanding of the relevant issues and/or concepts.
  • A response that uses terminology appropriately in places.
  • There is some evidence of analysis.
  • There is evidence that research has been undertaken.

10-12 marks - Proficient

  • A response with a detailed knowledge and clear understanding of the relevant issues and/or concepts.
  • A response that uses terminology appropriately throughout.
  • There is competent and balanced analysis.
  • Conclusions are drawn that are linked to the analysis.
  • There is clear evidence that extensive research has been undertaken.

Final points

  • My aim is to generate a couple of questions per challenge, and then assign them all out so that each student will have a different challenge question to start, and then rotate through them. All essays produced will be shared amongst your peers to assist in your mutual understanding of the case study.
  • It is quite an intense schedule, so the expectation is there is at-home contribution being made otherwise you won't get it done in time. In the three weeks I expect them to work at a pace of about 2 lessons research, 2 lessons essay drafting per assigned question. This means I don't expect all students will produce an essay per challenge in the three provided. (But I do make it clear that in their independent at-home revision time they should continue working through the essay practice questions) This is also why I share all the essays written. In week 5 I will have you review peer written papers for challenges they did not prepare responses for. The goal is that by the end of the assigned time they will have either authored or carefully reviewed an essay for each challenge.