CSCI N201 Programming Concepts and Database 2 - STAIR Lingma Acheson Department of Computer and Information Science, IUPUI

Problem Solving Technique Fundamental When you get stuck … When things go wrong …

What is STAIR? A problem solving strategy developed by faculty members here at the CS department Can be applied to a range of problems, e.g. real life problems, computer problems.

S – State the problem T – Tools A – Algorithm (ideas, plans, design charts, methods) I – Implementation (steps, actions) R – Refinement What does STAIR stand for?

Examples A real life example  My car broke S – T – A – I – R –  Your example?

Examples (2) Computer problems –My boss asked me to give him a quarterly sales report. –I’d like to create my own web pages.

Why do we need STAIR? The challenge of computers –Computers are not single tasked Can do many things (Word, , game, video…) –Changing pace of technology Hardware changes Software upgrades –Challenge of software diversity Do one thing in many different ways, which software to choose?

STAIR Is An Art Problem solving can be seen as more of an art than a science Each person has different ways of approaching and solving problems Plan for complicated problems Give you a framework to start with and to fall back on when you are stuck

STAIR Is An Art Skilled computer users are skilled problem solvers They rely on their ability to solve new problems and find answers independently than on previous knowledge of the commands of an application program

Seems obvious enough, but often the one people skip We frequently start solving problems before we really think carefully about what problem we are trying to solve Take the time to describe carefully to yourself what you are trying to accomplish –Be clean and concise –Be complete S - State the Problem

Avoid the temptation to phrase the problem in technical terms –Use simple English Use whatever you need to make sure you have a firm understanding of your problem –Write down the problem –Make a diagram or flowchart –Draw a sketch Usually the hardest step! Quarterly sales report: What is the problem?

A tool can be anything –Commands –Button on a toolbar –Programs –People –Resources Identify some tools List all potential tools –New tools can be added as your gain experience Be imaginative! T – Tools for the Job

Know your tools well –Have a strong general knowledge about how computers work and what they can and what they can’t do –Know the main types of applications that are used –Know what features they can expect to find within an application Quarterly sales report: What tools do you need? T – Tools for the Job

Computer word for plan/strategy Re-state of problem in terms of tools – how to use tools List of steps What to do in each step Can be as simple as one sentence for less complex problems or a complete action plan for more complex problems Quarterly sales report: What’s your plan? A – Algorithm Development

Just do it! Translate algorithm into action The easiest step! Quarterly sales report: Time to use the computer! I – Implementation of the Algorithm

It never goes right the first time Quarterly sales report: Why my boss don’t like it? Look back over previous steps and analyze what happened –Did you define the problem properly? –Did you choose the right tool? Have you used all the possible tools? –Is your algorithm correct? Did you choose the best algorithm? –Did you implement the solution properly? Fix problems and try again R – Refinement

Each unsuccessful attempt should bring you closer to an understanding of the problem and its solution Practice makes you much more confident R – Refinement

State the problem – Define with words, sketches or other means Tools – Identify commands, programs, resources that can help you solve the problem Algorithm – Come up with an action plan Implementation – Carry out the action plan Refinement – Make it better STAIR Revisit