1 Course Summary Fall 2005 CS 101 Aaron Bloomfield.

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Course Summary

Course SummaryFall 2005CS 101Aaron Bloomfield

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Course ReflectionCourse Reflection

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Course goals Objectives: Students who complete the course will:

Understand fundamentals of programming such as variables, conditional and iterative execution, methods, etc.

Understand fundamentals of object-oriented programming in Java, including defining classes, invoking methods, using class libraries, etc.

Be aware of the important topics and principles of software development.

Have the ability to write a computer program to solve specified problems.

Be able to use the Java SDK environment to create, debug and run simple Java programs.

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Unstated course goals Everybody needs to have a “base” level of programming to

continue on in the CS courses (or as required by other departments) CS 101 and 201 provide that “base” level

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What was new this semester Test code required

In hindsight, this should have been explained better More TA office hours

This was well received by everybody Faculty mini-talks

Had trouble scheduling this in a coherent way, so only one happened this semester. Should I do more?

Labs Many were improved upon, and a few were added

Increased number of HWs by 2 Final few assignments were for a common big program

In hindsight, we see a better way to implement this next semester

Changing of the order the chapters were gone over

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Changes on deck for next semester Will keep (and improve upon) all the stuff from the last slide Study groups

The idea is a way for people to study and/or work together This does NOT mean group assignments, however

There were not enough people to make this work this semester Probably will ditch CodeLab - it didn’t work as well as I had hoped

It’s a good idea, but a real pain to manage properly I want to talk about debugging more

We are considering a site license for the debugging version of JCreator

Better web site design (it’s in development now – thoughts?) Will most likely lower the number of midterms to two (and require

the final) Want to put more diagrams in the slides (make them more visual) Will have the TAs give review sessions before the tests Might have forums/newsgroups on the website

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What didn’t work this semester I botched a lecture back in September (in chapter 3)

With this fixed, I’ll have freed up one more lecture session Plus one for the removed midterm

A number of things worked, but need improvement (mentioned before): Implementation of the game Faculty mini-talks Required test code

The semester schedule (i.e. Thanksgiving break) made it difficult to properly teach arrays There wasn’t a HW on 1-D arrays as a result This won’t be a problem in the spring, but will be next fall

Had a bit of trouble keeping the lectures interesting towards the end of the semester

Want to lower the amount of student frustration

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What did work this semester This class learned much more than last semester’s class did

Even if you feel confused now, take my word for it And as my goal is to teach (and not to be popular), this is

a good thing Changing of the order the chapters were gone over Improved TA office hours Improvements to the labs Grading system worked very well this semester All the code on the website Many things that were “behind the scenes”

TA organization and utilization Grading system Me delegating the work better to the TAs

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Did I push too hard this semester? I pushed the class much harder this semester than last

semester But did I push too hard? Consider:

I’ve gotten as many “things are going great” comments as I have “things are too hard” comments (anecdotal)

Homeworks took under 5 hours on average The results from the survey questions for each HW

There were 8 HWs over about 16 weeks That’s 2.5 hours (on average) on homeworks per week

Ultimately, I think that with a bit better organization, I can lower the amount of time spent on the HWs while still having people learn the same amount

I’m interested in your feedback on this! But not today in lecture….

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The Big OOP PictureThe Big OOP Picture

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The classes for the game Creature (HW J6) Weapon (HW J6) Room (HW J7) Map (HW J8) Game (HW J8) Parser (lab 9) Descriptions (lab 10) MapPrinter (lab 11)

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How a big OOP program interacts Note how the classes interacted in the game A lot of objects were created and manipulated

A Room for each spot in the grid Creatures and Weapons for some of the Rooms A Map object Etc.

The way this game has objects interacting is how a big OOP program would work

Encapsulation The Room class didn’t need to know how the Creature

class kept track of whether the monster was angry or not It just called getAngry() and setAngry() It could have been stored as a boolean or an int

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Problem solving To solve a problem in CS, you break it down into smaller and smaller

pieces

A big program is broken down into packages Which we haven’t seen yet Consider the game to be one package

The packages are broken down into hierarchies This uses inheritance Our game didn’t use a hierarchy, as you did know of inheritance

at that point The hierarchies are broken down into classes

The game had 8 classes Each class is broken down into methods and variables

Some (such as MapPrinter) only had 1; others (such as Map) had dozens

Each method is broken down into parts, etc.

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The completed game This could easily be made by multiple people

Each person does a separate class Not exactly equal, but it still lowers the workload

Our (fully commented) code for the game was over 1,300 lines

However long yours was, it was a program greater than 1,000 lines Even if you had trouble getting parts working, and had to

use our code You still wrote part, and saw how it interacted with the rest

of the system

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Review of Chapter 1Review of Chapter 1

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Demotivator winners!Demotivator winners!

MethodologyMethodology– 11stst place vote counted for 3 points place vote counted for 3 points– 22ndnd place vote counted for 2 points place vote counted for 2 points– 33rdrd place vote counted for 1 point place vote counted for 1 point

Will buy two demotivators and hang Will buy two demotivators and hang them in my office…them in my office…

The results, with 137 of 173 The results, with 137 of 173 precincts reporting…precincts reporting…

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Engineering software Complexity of software grows as attempts are made to make

it easier to use

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Software engineering Goal

Production of software that is effective and reliable, understandable, cost effective, adaptable, and reusable

Goal Production of software that is effective and reliable,

understandable, cost effective, adaptable, and reusable

Work correctly and not fail



Because of the long lifetime many people will be involved Creation Debugging Maintenance Enhancement

Two-thirds of the cost is typically beyond creation



Cost to develop and maintain should not exceed expected benefit



Design software so that new features and capabilities can be added



Makes sense due to the great costs involved to have flexible components that can be used in other software

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Abstraction

Encapsulation

Modularity

Hierarchy

Abstraction

Encapsulation

Modularity

Hierarchy

Abstraction

Encapsulation

Modularity

Hierarchy

Abstraction

Encapsulation

Modularity

Hierarchy

Abstraction

Encapsulation

Modularity

Hierarchy

Separate components into external and internal

aspects

Construct a system fromcomponents and

packages

Ranking or ordering of objects

Principles of software engineering

Determine the relevant properties and

features while ignoring nonessential details

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Object-oriented design Purpose

Promote thinking about software in a way that models the way we think and interact with the physical word Including specialization

Object Properties or attributes Behaviors

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Programming Problem solving through the use of a computer system

Maxim You cannot make a computer do something if you do not

know how to do it yourself

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Problem Solving Process What is it?

Analysis Design Implementation Testing

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Determine the inputs, outputs, and other components of the problem

Description should be sufficiently specific to allow you to solve the problem

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Describe the components and associated processes for solving the problem

Straightforward and flexible

Method – process

Object – component and associated methods

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Develop solutions for the components and use those components to produce an overall solution

Straightforward and flexible

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Test the components individually and collectively

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Problem Solving Process

Testing

Design

Analysis

Implementation

Determineproblem features

Describe objectsand methods

Produce theclasses and code

Examine forcorrectness

Rethink asappropriate

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Tips Find out as much as you can

Reuse what has been done before

Expect future reuse

Break complex problems into subproblems

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Expect future reuse


Find out what is known about the problem

Talk to the presenter

Determine what attempts have succeeded and what attempts have failed

Research can require significant time and generate questions

The effort is worthwhile because the result is a better understanding

True understanding of the problem makes it easier to solve

Consider

Sketching a solution and then repeatedly refine its components until the entire process is specified

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Expect future reuse


Your time is valuable

Correctness is probably even more valuable

Use existing infrastructure that is known to work

Be open to indirect use of existing materials

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Expect future reuse


Make as few assumptions as necessary

Maximizes the likelihood that your effort can be used in future situations

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Tips

Divide-and-conquer

Solve subproblems and combine into an overall solution

Find out as much as you can


Expect future reuse


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Have a great holiday Have a great holiday break!break!

1 Course Summary Fall 2005 CS 101 Aaron Bloomfield.

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