Teaching Planning - Guide to Teaching Computer Science: An Activity-Based Approach - page 206

minology; the second list presents a list which is based on the computer science
education research literature.

Experiences of computer science educators :
• Confusion between the index and the content of an array-cell.
• Misconception: When an array is used, all its cells should be scanned.
• Misconception: Including the array variable in an output statement displays
all the array cell contents.
• When an array of objects is used, difficulties in understanding the need to
construct each object (even after the array of objects itself has already been
constructed).
• Difficulty to understand the algorithmic role of an array cell (e.g., a regular
value, a counter, an accumulator).
• A frequent mistake: exceeding the array index beyond the array size.
• A frequent mistake: loss of a value of an array-cell due to overwriting (e.g., in
the process of array sorting).
• A frequent mistake: When building a new array, leave empty cells in the “mid-
dle” instead of writing values successively (e.g., in intersection).
Examples from the computer science education literature :
Table 11.1 presents seven examples, taken from the computer science edu-
cation literature, that discuss students' difficulties and misconceptions with
respect to learning and teaching the concept of array. For each reference, we
suggest a possible implementation for the teaching planning of the study unit of
arrays.
3. Locate the concepts listed in Stage 1 along a time line, taking into the consider-
ations the difficulties recognized in Stage 2 .
4. Divide the list of concepts into a sequence of lessons, considering the total time
allocated for the teaching of the said topic .

These stages (the actual allocation of each topic on a time line and its division into
successive lessons) should be carried out according to learners' age and abilities,
the total time allocated for the study unit, the number of lab lessons, etc. In addi-
tion, it is important to include evaluation points along this time line and to decide
what kind of evaluation is appropriate for this case (e.g., tests, formative evaluation,
portfolio; see Chap. 10).

11.3.2 Planning the Teaching of the First Lesson

about One-Dimensional Array

The process of lesson planning is illustrated by the first lesson in the study unit
of one-dimensional array, and is carried out according to the consideration of the
aspects presented in Sect. 11.2.3. We assume that (a) the learners are high school
pupils, (b) the time allocated for this lesson is one and a half hour, and (c) the lesson
takes place in the computer lab.