DP CompSci: Case study


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.

2018 Case study: Autonomous vehicles

Dijkstra's algorithm animated
(sourced from http://www3.cs.stonybrook.edu/~skiena/combinatorica/animations/dijkstra.html)

Review resources

Structure of the paper

  • 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)
  • 1 x Extended answer question worth 12 marks 24 minutes.
    • Command terms: Compare, evaluate, discuss, to what extent

Objectives of class time

Dissect it

  • Identify topics for research - brainstorm padlet
  • Try to anticipate questions
  • Allocate topics to students. Have them present to the class.

Specialist terminology relevant to the case study

  • Study the extra vocab (not a shared thing, they should study each word themselves for best individual understanding)
  • Make sure you use the terminology and key words
  • Continual terminology quizzes

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).

Try and present some real experience to the technology involved.

  • Field trip
  • Have someone visit the class
  • It’s nice if they can say “when I saw...” (refer to something they’ve seen/done themselves).
  • Individual research.

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…
  • The last question will be based on extra challenges faced.
  • Dissect the challenges faced.
  • Brainstorm what questions could come from them
  • Put the topics on a piece of butcher paper. Give them a pad of post-it’s: green (good), red (bad), blue (interesting). Eg: Different operating systems: Windows, Mac, Linux, Android, iOS
  • The marking scheme for paper 3 / question 4 is generic – always the same (other than the italics in the last band) so give it to the students, make sure they have studied it. Use it in the marking scheme of my own exams.

Question 4 marking band

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.