Artificial Intelligence: A Modern Approach, 4th Edition
INSTRUCTOR’S SOLUTION MANUAL: EXERCISE
SOLUTIONS FOR ARTIFICIAL INTELLIGENCE A
MODERN APPROACH FOURTH EDITION BY STUART J.
RUSSELL AND PETER NORVIG LATEST UPDATE
2025/2026 A+
1
, Artificial Intelligence: A Modern Approach, 4th Edition
Solutions for Chapter 1
Introduction
1.1
a. Dictionary Definitions Of Intelligence Talk About ,The Capacity To Acquire And Apply
Knowledge‖ Or ,The Faculty Of Thought And Reason‖ Or ,The Ability To Comprehend
And Profit From Experience.‖ These Are All Reasonable Answers, But If We Want
Something Quantifiable We Would Use Something Like ,The Ability To Apply Knowledge
In Order To Perform Better In An Environment.‖
b. We Define Artificial Intelligence As The Study And Construction Of Agent Programs That
Perform Well In A Given Environment, For A Given Agent Architecture.
c. We Define An Agent As An Entity That Takes Action In Response To Percepts From An
Envi- Ronment.
1.2 See The Solution For Exercise 26.1 For Some Discussion Of Potential Objections.
The Probability Of Fooling An Interrogator Depends On Just How Unskilled The Interroga-
Tor Is. One Entrant In The 2002 Loebner Prize Competition (Which Is Not Quite A Real Turing
Test) Did Fool One Judge, Although If You Look At The Transcript, It Is Hard To Imagine What
That Judge Was Thinking. There Certainly Have Been Examples Of A Chatbot Or Other Online
Agent Fooling Humans. For Example, See See Lenny Foner’s Account Of The Julia Chatbot
At Foner.Www.Media.Mit.Edu/People/Foner/Julia/. We’d Say The Chance Today Is Something
Like 10%, With The Variation Depending More On The Skill Of The Interrogator Rather Than The
Program. In 50 Years, We Expect That The Entertainment Industry (Movies, Video Games, Com-
Mercials) Will Have Made Sufficient Investments In Artificial Actors To Create Very Credible
Impersonators.
1.3 The 2002 Loebner Prize (Www.Loebner.Net) Went To Kevin Copple’s Program ELLA. It
Consists Of A Prioritized Set Of Pattern/Action Rules: If It Sees A Text String Matching A
Certain Pattern, It Outputs The Corresponding Response, Which May Include Pieces Of The
2
, Artificial Intelligence: A Modern Approach, 4th Edition
Current Or Past Input. It Also Has A Large Database Of Text And Has The Wordnet Online
Dictionary. It Is Therefore Using Rather Rudimentary Tools, And Is Not Advancing The Theory Of
AI. It Is Provid-
3
, Artificial Intelligence: A Modern Approach, 4th Edition
Ing Evidence On The Number And Type Of Rules That Are Sufficient For Producing One Type Of
Conversation.
1.4 No. It Means That AI Systems Should Avoid Trying To Solve Intractable Problems. Usually,
This Means They Can Only Approximate Optimal Behavior. Notice That Humans Don’t Solve NP-
Complete Problems Either. Sometimes They Are Good At Solving Specific Instances With A Lot
Of
Structure, Perhaps With The Aid Of Background Knowledge. AI Systems Should Attempt To Do
The Same.
1.5 No. IQ Test Scores Correlate Well With Certain Other Measures, Such As Success In
College, But Only If They’re Measuring Fairly Normal Humans. The IQ Test Doesn’t Measure
Everything. A Program That Is Specialized Only For IQ Tests (And Specialized Further Only For
The Analogy Part) Would Very Likely Perform Poorly On Other Measures Of Intelligence. See
The Mismea- Sure Of Man By Stephen Jay Gould, Norton, 1981 Or Multiple Intelligences: The
Theory In Practice By Howard Gardner, Basic Books, 1993 For More On IQ Tests, What They
Measure, And What Other Aspects There Are To ,Intelligence.‖
1.6 Just As You Are Unaware Of All The Steps That Go Into Making Your Heart Beat, You Are
Also Unaware Of Most Of What Happens In Your Thoughts. You Do Have A Conscious Awareness
Of Some Of Your Thought Processes, But The Majority Remains Opaque To Your Consciousness.
The Field Of Psychoanalysis Is Based On The Idea That One Needs Trained Professional Help To
Analyze One’s Own Thoughts.
1.7
a. (Ping-Pong) A Reasonable Level Of Proficiency Was Achieved By Andersson’s Robot (An-
Dersson, 1988).
b. (Driving In Cairo) No. Although There Has Been A Lot Of Progress In Automated Driving,
All Such Systems Currently Rely On Certain Relatively Constant Clues: That The Road
Has Shoulders And A Center Line, That The Car Ahead Will Travel A Predictable Course,
That Cars Will Keep To Their Side Of The Road, And So On. To Our Knowledge, None Are
Able To Avoid Obstacles Or Other Cars Or To Change Lanes As Appropriate; Their Skills
Are Mostly Confined To Staying In One Lane At Constant Speed. Driving In Downtown Cairo
Is Too Unpredictable For Any Of These To Work.
c. (Shopping At The Market) No. No Robot Can Currently Put Together The Tasks Of Moving In
A Crowded Environment, Using Vision To Identify A Wide Variety Of Objects, And Grasping
4
INSTRUCTOR’S SOLUTION MANUAL: EXERCISE
SOLUTIONS FOR ARTIFICIAL INTELLIGENCE A
MODERN APPROACH FOURTH EDITION BY STUART J.
RUSSELL AND PETER NORVIG LATEST UPDATE
2025/2026 A+
1
, Artificial Intelligence: A Modern Approach, 4th Edition
Solutions for Chapter 1
Introduction
1.1
a. Dictionary Definitions Of Intelligence Talk About ,The Capacity To Acquire And Apply
Knowledge‖ Or ,The Faculty Of Thought And Reason‖ Or ,The Ability To Comprehend
And Profit From Experience.‖ These Are All Reasonable Answers, But If We Want
Something Quantifiable We Would Use Something Like ,The Ability To Apply Knowledge
In Order To Perform Better In An Environment.‖
b. We Define Artificial Intelligence As The Study And Construction Of Agent Programs That
Perform Well In A Given Environment, For A Given Agent Architecture.
c. We Define An Agent As An Entity That Takes Action In Response To Percepts From An
Envi- Ronment.
1.2 See The Solution For Exercise 26.1 For Some Discussion Of Potential Objections.
The Probability Of Fooling An Interrogator Depends On Just How Unskilled The Interroga-
Tor Is. One Entrant In The 2002 Loebner Prize Competition (Which Is Not Quite A Real Turing
Test) Did Fool One Judge, Although If You Look At The Transcript, It Is Hard To Imagine What
That Judge Was Thinking. There Certainly Have Been Examples Of A Chatbot Or Other Online
Agent Fooling Humans. For Example, See See Lenny Foner’s Account Of The Julia Chatbot
At Foner.Www.Media.Mit.Edu/People/Foner/Julia/. We’d Say The Chance Today Is Something
Like 10%, With The Variation Depending More On The Skill Of The Interrogator Rather Than The
Program. In 50 Years, We Expect That The Entertainment Industry (Movies, Video Games, Com-
Mercials) Will Have Made Sufficient Investments In Artificial Actors To Create Very Credible
Impersonators.
1.3 The 2002 Loebner Prize (Www.Loebner.Net) Went To Kevin Copple’s Program ELLA. It
Consists Of A Prioritized Set Of Pattern/Action Rules: If It Sees A Text String Matching A
Certain Pattern, It Outputs The Corresponding Response, Which May Include Pieces Of The
2
, Artificial Intelligence: A Modern Approach, 4th Edition
Current Or Past Input. It Also Has A Large Database Of Text And Has The Wordnet Online
Dictionary. It Is Therefore Using Rather Rudimentary Tools, And Is Not Advancing The Theory Of
AI. It Is Provid-
3
, Artificial Intelligence: A Modern Approach, 4th Edition
Ing Evidence On The Number And Type Of Rules That Are Sufficient For Producing One Type Of
Conversation.
1.4 No. It Means That AI Systems Should Avoid Trying To Solve Intractable Problems. Usually,
This Means They Can Only Approximate Optimal Behavior. Notice That Humans Don’t Solve NP-
Complete Problems Either. Sometimes They Are Good At Solving Specific Instances With A Lot
Of
Structure, Perhaps With The Aid Of Background Knowledge. AI Systems Should Attempt To Do
The Same.
1.5 No. IQ Test Scores Correlate Well With Certain Other Measures, Such As Success In
College, But Only If They’re Measuring Fairly Normal Humans. The IQ Test Doesn’t Measure
Everything. A Program That Is Specialized Only For IQ Tests (And Specialized Further Only For
The Analogy Part) Would Very Likely Perform Poorly On Other Measures Of Intelligence. See
The Mismea- Sure Of Man By Stephen Jay Gould, Norton, 1981 Or Multiple Intelligences: The
Theory In Practice By Howard Gardner, Basic Books, 1993 For More On IQ Tests, What They
Measure, And What Other Aspects There Are To ,Intelligence.‖
1.6 Just As You Are Unaware Of All The Steps That Go Into Making Your Heart Beat, You Are
Also Unaware Of Most Of What Happens In Your Thoughts. You Do Have A Conscious Awareness
Of Some Of Your Thought Processes, But The Majority Remains Opaque To Your Consciousness.
The Field Of Psychoanalysis Is Based On The Idea That One Needs Trained Professional Help To
Analyze One’s Own Thoughts.
1.7
a. (Ping-Pong) A Reasonable Level Of Proficiency Was Achieved By Andersson’s Robot (An-
Dersson, 1988).
b. (Driving In Cairo) No. Although There Has Been A Lot Of Progress In Automated Driving,
All Such Systems Currently Rely On Certain Relatively Constant Clues: That The Road
Has Shoulders And A Center Line, That The Car Ahead Will Travel A Predictable Course,
That Cars Will Keep To Their Side Of The Road, And So On. To Our Knowledge, None Are
Able To Avoid Obstacles Or Other Cars Or To Change Lanes As Appropriate; Their Skills
Are Mostly Confined To Staying In One Lane At Constant Speed. Driving In Downtown Cairo
Is Too Unpredictable For Any Of These To Work.
c. (Shopping At The Market) No. No Robot Can Currently Put Together The Tasks Of Moving In
A Crowded Environment, Using Vision To Identify A Wide Variety Of Objects, And Grasping
4
