1. PPT6: Scientific debugging
CEN 4072
Software Testing
PPT6: Scientific debugging
PPT and video are due: no later than October 5, 5:00 PM
Submit to:
This template file is just an outline of the presentation
that you need to complete. Additional pages will
be necessary to fully explore the topic above.
Each page should contain adequate text as well
as illustrations. You are free to use all publically
available information (text as well as graphics) as long as
the sources are properly acknowledged.

2. Team members’ contributions
Member [name]:

3. Errors
Content outline:
What is an error in the software

4. Causes and effects Content outline: What is the cause of a problem?
Examples

5. Causes and effects
Content outline:
How to prove causality?
Example

6. Causality Content outline: Repeating history
Can we repeat history in software?

7. Causality Content outline: Repeating program runs
How much data and knowledge does it take?

8. Causes by intuition Content outline: Can intuition be taught?
What is tacit knowledge and how one would acquire it?

9. Scientific method: what is it?
Content outline:
Explanation and examples

10. Scientific method: main steps
Content outline:
Steps and their explanations in using the scientific method

11. What is a theory?
Content outline:
The road from hypothesis to theory

12. Scientific method of debugging
Content outline:
Details, explanation and chart

13. Sample program revisited
int main(int argc, char *argv[]) {
int *a;
int i;
a = (int *)malloc((argc - 1) * sizeof(int));
for (i = 0; i < argc - 1; i++)
a[i] = atoi(argv[i + 1]);
shell_sort(a, argc);
printf("Output: ");
printf("%d ", a[i]);
printf("\n");
free(a);
return 0; }
static void shell_sort(int a[], int size) {
int i, j;
int h = 1;
do {
h = h * 3 + 1;
} while (h <= size);
h /= 3;
for (i = h; i < size; i++)
int v = a[i];
for (j = i; j >= h && a[j - h] > v; j -= h)
a[j] = a[j - h];
if (i != j)
a[j] = v; }
} while (h != 1);

14. Debugging with the scientific method
Content outline:
Detailed steps of how to use the scientific method to debug the sample program

15. Explicit debugging Content:
Stating the problem explicitly can help solve the problem
The Teddy Bear principle of software

16. Keep a notebook Content outline:
Keep a record of each debugging session

17. Algorithmic debugging
Content outline:
Steps of the algorithmic debugging

18. Example code for algorithmic debugging
def insert(elem, list):
if len(list) == 0:
return [elem]
head = list[0]
tail = list[1:]
if elem <= head:
return list + [elem]
return [head] + insert(elem, tail)
def sort(list):
if len(list) <= 1:
return list
head = list[0]
tail = list[1:]
return insert(head, sort(tail))

19. Algorithmic debugging session
Content outline:
Step-by-step debugging of the sample code above
Include an explanation as well as a chart

20. Pros and Cons Content outline:
Pros and cons of the scientific debugging

21. Obtaining a hypothesis
Content outline:
Observing a run
Deducing from the code
Problem report
Earlier hypotheses

22. Reasoning about the programs: deduction
Content outline:
Details on how to use deduction
Example

23. Reasoning about the programs: observation
Content outline:
Details on how to use observation
Example

24. Reasoning about the programs: induction
Content outline:
Details on how to use induction
Example

25. Reasoning about the programs: experimentation
Content outline:
Details on how to use experimentation
Example

26. Your code experimentations
Content outline:
Share your experience(s) with experiments
Examples