Backward Mapping in IBDP Computer Science

The backward mapping technique allows us to produce quality lessons for our students, designed and aimed purposefully to help them meet the standards determined by schools and/or state.  In my currently teaching Year 1 (Grade 11) Computer Science following the International Baccaulerate diploma programme. For my specific case, those standards are the one determined by the IB organization, in their IBDP Computer Science guide.  These standards are the ones students are expected to be able to use in their final examinations, and internal examinations in order to be granted with credit for completion of the course.

I will be illustrating the backward mapping process in this post through the use of one of said standards. Specifically, standard 2.1.4: Describe the stages of the fetch-execute cycle, including the use of registers.  

The reason why I chose this standard is because is a complex topic normally new for students taking the course, and it could be a challenging one if not approached appropriately.  Additionally, this is one of the standards I will be teaching in my next unit, and I think is just common sense to try and use something that will be useful and meaningful for my work.

In preparation for designing this activity, additional to the IBDP Computer Science mentioned before, I have supported my design with the Syllabus and Scheme of work provided by Cambridge, for the IGCSE Computer Science course 0478.  I’ve chosen these documents, as this is a topic common between the 2 curriculums, both in its content and in its approach.  Additionally, I am also teaching the IGCSE CS Curriculum to 10^th grade students (year 2 of this course), so I believe this planning will be helpful as well, for the future or other teachers, teaching this lesson to 9^th grade students (with some modification on the assessments).

Stage 1:  By unpacking the standard, the following Big Ideas, skills, knowledge and understandings were identified for the standard:

Big Ideas:

·             Stages of the fetch-execute cycle
        Use of registers in the fetch-execute cycle

Key Knowledge/Skills/Understandings

Skills - Students should be able to	Knowledge -  Students will know:	Understandings – Students will understand
Identify the computers components involved in each one of the stages of the fetch-execute cycle. Describe each one of the stages in the fetch-execute cycle. Explain how data is transmitted from one stage to the next one in the fetch-execute cycle. Explain the function of the different registers in each one of the stages of the fetch-execute cycle.	The different components of the CPU and primary memory involved in the fetch-execute cycle. The different stages of the fetch-execute cycle.	that every process in a computing system needs to be broken down to fundamental tasks that can be executed on a fetch-execute cycle. the different roles of the CPU and the main memory in the fetch-execute cycle.

These leads to the following proficiencies identified for the standard:

• By the end of the unit students will be able to explain each one of the different stages of the fetch-execute cycle.
• By the end of the unit students will be able to identify the components involved in each one of the stages of the fetch-execute cycle.
• By the end of the unit students will be able to describe the contents of different registers during each one of the stages of the fetch-execute cycle.

Stage 2:

After identifying the learning objectives, we proceed with designing assessments that will help us know if the students are meeting the standard

Examples of some of the possible assessments for this standard are:

• Performance task/project:  Students use a LMC (Little Man Computer) software to carry out a low level task that allows them to track the changes made to specific registers during a small series of fetch-execute cycles.
• Quiz:  Students will take a quiz with exam type questions checking for understanding of the concepts.  Quiz could also check for register names and its uses.
• Observation:  Students work in groups practicing to track the content of registers during a fetch-execute cycle.  Teacher keeps an observation journal looking for misconceptions.
• Performance task/project:  Students create their own visual representation of the fetch-execute cycle, containing descriptions of the components involved and the actions involved on each stage.

Stage 3:

Finally, based on the assessments we are expecting students to complete, we identify the activities or learning experiences we will create in our classroom to help students meet the standard.

The following are potential activities linked to the expected outcomes in the evaluations designed in the previous stage:

• Teacher demonstrates each one of the stages with the use of a java program or a LMC program.
• Teacher and students role-play the fetch-execute cycle for a short program, acting as components of a CPU or main memory.  They can “hold” registers values on a small white board.
• Students create one-pagers for each one of the names of the components and registers’ names, as a strategy for vocabulary building for SLL students.

In conclusion, and after following the UbD design, it is possible to come up with a teaching plan that is purposefully designed to comply with the standards stablished by the IBDP program.

References:

Hidden curriculum (2014, August 26). In S. Abbott (Ed.), The glossary of education reform. Retrieved from http://edglossary.org/hidden-curriculum
McTighe, A. (1997). Assessment Framework [PDF]. Washington: National Education Association.
Wiggins, G. (2003). Overview of UbD & the Design Template [PDF]. ASCD.