1. NECC ForumJune, 2008 © Chris Stephenson Teaching Problem Solving and Design Chris Stephenson Computer Science Teachers Association

2. NECC ForumJune, 2008 © Chris Stephenson The Goal A primary goal of curriculum reform is to create classrooms in which students: u are challenged to think critically u learn how to discover, understand, and analyze u apply skills and knowledge in new situations

3. NECC ForumJune, 2008 © Chris Stephenson Computer Programming u Problem solving skills are absolutely key to program development u The most fundamental obstacles to learning to program are related to problem solving BUT!!! u Most courses still focus on syntax!

4. NECC ForumJune, 2008 © Chris Stephenson Early Models of Problem Solving The first problem solving models broke down into two distinct approaches: u the traditional scientific method u an introspective creative method Scientists often report using both methods to enable discovery

5. NECC ForumJune, 2008 © Chris Stephenson The Scientific Process Dewey (1910): u define the problem u suggest possible solutions and identify alternative u reason about the solutions u implement u test and prove

6. NECC ForumJune, 2008 © Chris Stephenson The Creative Process Wallas (1926): u problem formulation and information gathering u incubation - allowing the unconscious to work on it u illumination - working to gain insight u verification - testing for accuracy

7. NECC ForumJune, 2008 © Chris Stephenson Polya (1945 and 1962) was the first to describe a problem solving model based on classroom experience: u understand the problem u devise a plan u carry out plan u look back Classroom Model

8. NECC ForumJune, 2008 © Chris Stephenson Students Need to Know u What programming is u The importance of style u How computers solve problems u How programmers develop software u Software development over time

9. NECC ForumJune, 2008 © Chris Stephenson Programming is... u Analyzing a problem to be solved. u Preparing a design for the steps in a set of instructions (an algorithm) u Expressing the algorithm in a language that the computer can ultimately execute u Providing adequate documentation u Testing and validating the program u Maintaining the program over time

10. NECC ForumJune, 2008 © Chris Stephenson How Computers Solve Problems Memory Processing InputOutput

11. NECC ForumJune, 2008 © Chris Stephenson Software Development Specification Architecture Untested Software Product Design Analysis Implementation Testing Maintenance The Waterfall Model

12. NECC ForumJune, 2008 © Chris Stephenson Iterative Model Marketing Implementation Design Testing Requirements Software Release Analysis Specification Product (Repeat) Architecture

13. NECC ForumJune, 2008 © Chris Stephenson Methodology The most common methods used for teaching problem solving and critical thinking skills are: u hands-on experience u real world problems u cooperative learning