BIS2040 final session: Revision and exam preparation

1
BIS2040 final sessionRevision and exam
preparation
2
The exam

• A two hour paper
• Five questions on the paper
• You will choose three out of the five
• Expect each question to have several parts -
  usually (a), (b) ( c)
• There wont be any questions on neural nets

3
Exam technique

• Dont be tempted to do less than three questions
• However well you do on the questions you attempt,
  youll lose more marks than you could have gained
  by doing a third question

4
Exam technique

• Dont be tempted to do more than three questions
• If you do, the marker will simply ignore your
  last answer
• So your last answer would be a complete waste of
  time and effort

5
Exam technique

• Try to write something on each part of the
  questions that you choose
• The marks beside each part of the question are a
  guide as to how much time its worth spending on
  that part of the question.

6
Exam technique

• You should pick your questions carefully,
  avoiding any that look hard
• All the questions carry equal marks, so theres
  no advantage to picking a hard question.

7
Exam technique

• You should spend about 35 minutes on each
  question.
• This gives you 5 minutes choosing time at the
  start, and
• 10 minutes finishing-off time at the end.

8
Exam technique

• You need to be quite sure you grasp what a
  question is about, before you start to answer it.

9
Subject matter

• The exam will cover topics that have been covered
  in the lectures
• Not Kappa-PC - that was covered by the
  coursework, and wont be in the exam

10
Subject matter

• The material in the Module Handbook should be
  enough to cover any of the answers to any of the
  questions
• If you go beyond the material in the handbook,
  using other material that youve read, thats
  fine, and liable to get you extra marks.

11
Exam technique

• Sometimes a student reads the question, and
  remembers something that sounds vaguely similar,
  and writes about that.
• If the question says describe the techniques of
  knowledge elicitation and you write about the
  techniques of knowledge representation, you wont
  get any marks.

12
Major themes in the course

• The nature of knowledge-based systems
• and of skill, and expertise
• and experts
• Expert systems advantages and risks
• The architecture of expert systems
• their reasoning mechanisms
• other features that make them work

13
Major themes in the course

• The various different forms of knowledge
  representation
• logic
• rules (rules are particularly important)
• semantic nets
• frames
• Case-based reasoning
• what it is
• how it differs from rule-based reasoning

14
Major themes in the course

• Knowledge acquisition
• how its done
• why its difficult
• what the techniques are
• Neural networks
• what they consist of
• what theyre good for
• what they can and cant do
• Examples of expert systems

15
Exam strategy

• The pattern in recent exams has been that there
  has been a whole exam question devoted to each of
  the following topics
• case-based reasoning
• knowledge elicitation
• knowledge representation using rules
• knowledge representation using other things
• the nature architecture of KBS

16
Exam strategy

• This suggests that you dont need to learn the
  whole syllabus.
• You could just pick certain lectures, covering
  certain topics, and thoroughly master the content
  of them so that you feel reasonably confident of
  answering likely questions in that field.
• You could just pick three topics (which is risky)
  or four topics (which is safer).

17
Major themes in the course

• The nature of knowledge-based systems
• and of skill, and expertise
• and experts
• Expert systems advantages and risks

18
Major themes in the course
The sort of answer that is required Short
written pieces, explaining concepts, or
explaining how and why things are done the way
they are in the expert systems business. Chapter
1 material, and distinctive features from
chapter 3.

• The nature of knowledge-based systems
• and of skill, and expertise
• and experts
• Expert systems advantages and risks

19
Major themes in the course

• The architecture of expert systems
• their reasoning mechanisms
• other features that make them work

20
Major themes in the course
Could be part of a question - unlikely to be
more. The sort of answer that is required Short
written pieces, explaining concepts, or diagrams.

• The architecture of expert systems
• their reasoning mechanisms
• other features that make them work

21
Major themes in the course

• The various different forms of knowledge
  representation
• rules (rules are particularly important)

22
Major themes in the course
Expect a whole question on rule-based
reasoning. The sort of answer that is
required Short written pieces, explaining
concepts. Likely to be at least one skills
part. Chapter 2 chap. 3 material.

• The various different forms of knowledge
  representation
• rules (rules are particularly important)

23
Major themes in the course

• The various different forms of knowledge
  representation
• logic
• semantic nets
• frames

24
Major themes in the course
Expect a whole question on non-rule-based
knowledge representation. The sort of answer that
is required Mostly skills answers -short
written pieces are rare in this section. Chapter
4 material.

• The various different forms of knowledge
  representation
• logic
• semantic nets
• frames

25
Major themes in the course

• Case-based reasoning
• what it is
• how it works
• how it differs from rule-based reasoning

26
Major themes in the course
Expect a whole question on case-based
reasoning. The sort of answer that is
required Short written pieces, explaining
concepts. Alternatively, short case
histories. Chapter 9 material.

• Case-based reasoning
• what it is
• how it works
• how it differs from rule-based reasoning

27
Major themes in the course

• Knowledge acquisition
• how its done
• why its difficult
• what the techniques are

28
Major themes in the course
Expect a large part of a question on knowledge
acquisition. Related topics, like system
development e.s. shells, might provide the
other parts. The sort of answer that is
required Short written pieces, explaining
concepts. Chapter 6, 7 8 material.

• Knowledge acquisition
• how its done
• why its difficult
• what the techniques are

29
Major themes in the course

• Examples of expert systems

30
Major themes in the course
Not likely to be given a question on its own. If
it appears at all, likely to be part of another
question. The sort of answer that is
required Short case histories or
comparisons Chapter 5 chap.9 material.

• Examples of expert systems

31
Major themes in the course

• Neural networks
• what they consist of
• what theyre good for
• what they can and cant do

32
Major themes in the course

• Neural networks
• what they consist of
• what theyre good for
• what they can and cant do

But this wont be in the exam
33

• skill questions

34
Skill 1 the draw up a frame system question

• Question
• A colour scientist is interviewed. Part of the
  interview transcript reads as follows

35
Skill 1 the draw up a frame system question

• "We can think of colours as warm colours, cold
  colours and pseudo colours. Warm colours include
  reds and yellows. Cold colours include greens and
  blues. Magentas are pseudo colours. Actually,
  it's probably best to think of warm colours and
  cold colours as different sorts of true colour,
  as opposed to pseudo colours.

36
Skill 1 the draw up a frame system question

• "Every colour has a saturation and a luminosity.
  And every colour has two CIE coordinates x and y
  - they're numbers, between zero and one. Every
  true colour has a dominant wavelength.

37
Skill 1 the draw up a frame system question

• "For example, this is a green it's called
  Wratten 58 Green. Its dominant wavelength is
  540.3 nanometres, its saturation is 86.2, its
  luminosity is 23.7, its CIE coordinates are X
  0.24 and Y 0.70. What about white? Well, I
  suppose I'd call that a pseudo colour, because it
  hasn't got a dominant wavelength. Its CIE
  coordinates are 0.33 and 0.33."

38
Skill 1 the draw up a frame system question

• Provide a description of a frame system which
  represents this information.

39
Skill 1 the draw up a frame system question

• Whats it all about?

40
Skill 1 the draw up a frame system question

• Whats it all about?
• Colours.
• Therefore all the frames in this system will be
  types of colour, or examples of colour.

41
Skill 1 the draw up a frame system question

• What types of colour, and what examples of
  colours, are mentioned?

42
Skill 1 the draw up a frame system question

• What types of colour, and what examples of
  colours, are mentioned?
• Types
• warm, cold, pseudo, reds, yellows, greens, blues,
  magentas, true, whites
• Examples
• Wratten 58 Green
• - each of these will be a frame in its own
  right.

43
Skill 1 the draw up a frame system question

• What are the qualities that describe all colours?

44
Skill 1 the draw up a frame system question

• What are the qualities that describe all colours?
• Saturation, luminosity, CIE coordinate X, CIE
  coordinate Y
• - each of these will be a slot in the top-level
  frame colours
• - the value, in each case, will be ?,
• meaning its different for every colour, so
  you really cant say what it is for colours in
  general

45
Skill 1 the draw up a frame system question

• Are there any other qualities that describe some,
  but not all, of the colours?

46
Skill 1 the draw up a frame system question

• Are there any other qualities that describe some,
  but not all, of the colours?
• Yes - dominant wavelength
• - This will be a slot in the frame true
  colour. Its value will be ?.

47
Skill 1 the draw up a frame system question

• Are any restrictions on permitted values
  mentioned?

48
Skill 1 the draw up a frame system question

• Are any restrictions on permitted values
  mentioned?
• Yes - a CIE coordinate X has to be a number
  greater than 0 and less than 1, and so does a CIE
  coordinate Y.

49
Skill 1 the draw up a frame system question

• What are the subclass_of relations for all the
  frames we listed earlier?

50
Skill 1 the draw up a frame system question

• What are the subclass_of relations for all the
  frames we listed earlier?
• ...warm colours and cold colours are different
  sorts of true colour
• ...Warm colours include reds and yellows. Cold
  colours include greens and blues. Magentas are
  pseudo colours.
• etc

51
Skill 1 the draw up a frame system question

• Listing all these relationships, we have
• warm colour is a subclass of true colour
• cold colour is a subclass of true colour
• pseudo colour is a subclass of colour
• reds is a subclass of warm colour
• yellows is a subclass of warm colour
• greens is a subclass of cold colour
• blues is a subclass of cold colour
• magentas is a subclass of pseudo colour
• true is a subclass of colour
• whites is a subclass of pseudo colour

52
Skill 1 the draw up a frame system question

• and
• Wratten 58 Green is an instance of green

53
Skill 1 the draw up a frame system question

• Putting this all together, we have the following
  frames

Name colour Subclass_of thing
Slots Name
Value Restrictions saturation
? Luminosity ? CIE coordinate X ? gt0,
lt1 CIE coordinate Y ? gt0, lt1
54
Skill 1 the draw up a frame system question
Name true colour Subclass_of
colour Slots Name
Value Restrictions dominant
wavelength ?
55
Skill 1 the draw up a frame system question
Name pseudo colour Subclass_of
colour
Name warm colour Subclass_of true colour
Name cold colour Subclass_of true colour
Name magenta Subclass_of pseudo
colour
56
Skill 1 the draw up a frame system question
Name red Subclass_of warm
colour
Name yellow Subclass_of warm colour
Name green Subclass_of cold
colour
Name blue Subclass_of cold colour
57
Skill 1 the draw up a frame system question
Name white Subclass_of pseudo
colour Slots Name
Value Restrictions CIE coordinate X
0.33 CIE coordinate Y 0.33
58
Skill 1 the draw up a frame system question
Name Wratten 58 Green Instance_of
green Slots Name
Value Restrictions saturation 86.2 lu
minosity 23.7 CIE coordinate X 0.33 CIE
coordinate Y 0.33 dominant wavelength 540.3 nm
59
Skill 2 the draw up a semantic net question

• Question
• Draw a semantic net which expresses the
  information in the following piece of text

60
Skill 2 the draw up a semantic net question

• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

61
Skill 2 the draw up a semantic net question

• Step 1 - locate the things
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

62
Skill 2 the draw up a semantic net question

• Step 1 - locate the things
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

63
Skill 2 the draw up a semantic net question

• Step 1 - locate the things
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

64
Skill 2 the draw up a semantic net question

• Step 1 - locate the things
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

65
Skill 2 the draw up a semantic net question

• Step 1 - locate the things
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

66
Skill 2 the draw up a semantic net question

• Step 1 - locate the things
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

67
Skill 2 the draw up a semantic net question

• Step 1 - locate the things
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

68
Skill 2 the draw up a semantic net question

• Step 1 - locate the things
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

69
Skill 2 the draw up a semantic net question

• Step 1 - locate the things
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

70
Skill 2 the draw up a semantic net question

• Step 1 - locate the things
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

71
Skill 2 the draw up a semantic net question

• Step 1 - locate the things
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

72
Skill 2 the draw up a semantic net question

• Step 2 - locate the relationships
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

73
Skill 2 the draw up a semantic net question

• Step 2 - locate the relationships
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

74
Skill 2 the draw up a semantic net question

• Step 2 - locate the relationships
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

75
Skill 2 the draw up a semantic net question

• Step 2 - locate the relationships
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

76
Skill 2 the draw up a semantic net question

• Step 2 - locate the relationships
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

77
Skill 2 the draw up a semantic net question

• Step 2 - locate the relationships
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

78
Skill 2 the draw up a semantic net question

• Step 2 - locate the relationships
• Turning to Nabisco, Nabisco is a biscuit
• company operating in the UK. Like other
• food companies, biscuit companies have
• to meet stringent quality standards.
• Nabisco has three major competitors.
• Among other things, Nabisco makes
• cookies, and cookies are a specialised
• product sold to select consumer
• groups.

Nabisco operates_in UK Food company have_to_meet s
tringent quality standards Nabisco makes cookie Sp
ecialised product sold_to select consumer group
79
Skill 2 the draw up a semantic net question

• Step 2 - locate the relationships
• Turning to Nabisco, Nabisco is a biscuit
• company operating in the UK. Like other
• food companies, biscuit companies have
• to meet stringent quality standards.
• Nabisco has three major competitors.
• Among other things, Nabisco makes
• cookies, and cookies are a specialised
• product sold to select consumer
• groups.

Nabisco operates_in UK Food company have_to_meet s
tringent quality standards Nabisco makes cookie Sp
ecialised product sold_to select consumer group
major_competitor1 Nabisco has
major_competitor2 major_competitor3
80
Skill 2 the draw up a semantic net question

• Step 3 - locate the implied relationships
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

81
Skill 2 the draw up a semantic net question

• Step 3 - locate the implied relationships
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

Nabisco instance of biscuit company
82
Skill 2 the draw up a semantic net question

• Step 3 - locate the implied relationships
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

biscuit company is a food company
83
Skill 2 the draw up a semantic net question

• Step 3 - locate the implied relationships
• Turning to Nabisco, Nabisco is a biscuit company
  operating in the UK. Like other food companies,
  biscuit companies have to meet stringent quality
  standards. Nabisco has three major competitors.
  Among other things, Nabisco makes cookies, and
  cookies are a specialised product sold to select
  consumer groups.

cookie is a specialised product
84
Skill 2 the draw up a semantic net question

• Youre now in a position to draw the diagram.
  Each of the things is given its own box, and
  written in

85
Major competitor 1
Stringent quality standards
Food company
Major competitor 2
Biscuit company
Nabisco
Nabisco
Major competitor 3
UK
Cookie
Select consumer group
Specialised product
86
Skill 2 the draw up a semantic net question

• The boxes are joined together using arrows - its
  important the the arrows point in the right
  direction. If a biscuit company is a food
  company. Then the arrow that will be called isa
  points from biscuit company to food company.

87
Major competitor 1
Stringent quality standards
Food company
Major competitor 2
Biscuit company
Nabisco
Nabisco
Major competitor 3
UK
Cookie
Select consumer group
Specialised product
88
Skill 2 the draw up a semantic net question

• Finally, each arrow is given an appropriate
  label

89
Major competitor 1
Stringent quality standard
Food company
has_to_meet
has
Major competitor 2
isa
has
Biscuit company
instance_of
Nabisco
Nabisco
Major competitor 3
has
makes
operating_in
UK
Cookie
isa
Select consumer group
Specialised product
sold_to
90
Skill 3 the draw up an and-or chart question

• Question
• Here are some rules describing the macroeconomic
  functioning of the British economy. Draw an
  and-or chart representing this information.

91
If exports decrease or imports increase or public
spending increases, then the budget needs more
money. If production decreases, then exports
decrease. If workers incentives decrease then
production decreases. If taxes increase or real
wages decrease then workers incentives decrease
. If import prices decrease then imports
increase. If the pound rises then import prices
decrease. If the housing shortage increases or
real rates decrease then public spending
increases.
92
Skill 3 the draw up an and-or chart question

• Step 1 decide what the ultimate conclusion (the
  final piece of advice) is.
• This may be obvious.
• If it isnt obvious, the task is to find a rule
  whose conclusion isnt the condition for any of
  the other rules.
• In this case, its this one

93
If exports decrease or imports increase or public
spending increases, then the budget needs more
money. If production decreases, then exports
decrease. If workers incentives decrease then
production decreases. If taxes increase or real
wages decrease then workers incentives decrease
. If import prices decrease then imports
increase. If the pound rises then import prices
decrease. If the housing shortage increases or
real rates decrease then public spending
increases.
94
Skill 3 the draw up an and-or chart question

• The conclusion that youve just located belongs
  in a box at the top of your diagram.
• The conditions of this rule each go into a box
  immediately below the top box in the diagram.

95
Skill 3 the draw up an and-or chart question
The budget needs more money
Exports decrease
Imports increase
Public spending increases
96
Skill 3 the draw up an and-or chart question

• Notice that, because the conditions had the word
  or between them, the lines leading down to the
  next row of boxes arent connected by an arc.
• If the conditions had had the word and between
  them, the lines would have been connected by an
  arc.

97
Skill 3 the draw up an and-or chart question

• From now on, its a question of extending the
  diagram downwards.
• If any on the boxes in the bottom row is the
  conclusion of another rule, follow the same
  procedure to draw some boxes underneath it.

98
Skill 3 the draw up an and-or chart question

• For instance, there is a box in the bottom row
  like this
• Is there a rule that has this as its conclusion?
  Yes
• If production decreases, then exports decrease.
• So the box gets another
• box underneath it

Exports decrease
Exports decrease
Production decreases
99
Skill 3 the draw up an and-or chart question

• For instance, there is a box in the bottom row
  like this
• Is there a rule that has this as its conclusion?
  Yes
• If the housing shortage increases or real
  rates decrease then public spending increases.
• So the box gets another
• 2 boxes underneath it

Public spending increases
Public spending increases
Housing shortage increases
Real rates decrease
100
Skill 3 the draw up an and-or chart question

• Repeat this until youve covered all the rules
  that you were given.
• Its a good idea to cross out each rule as you
  deal with it. When all the rules are crossed out,
  the diagram should be complete.

101
Skill 4 the turn this logic statement into
English question

• You need to know what the logic symbols mean
• ? means and
• ? means or
• ? means if then ...
• ? means if and only if ...
• ? means not

102
Skill 4 the turn this logic statement into
English question

• You need to know that a predicate adds a quality
  to an item, or specifies a relationship between
  two (or more) items)
• If H stands for happy and A stands for Andy,
  then
• H(A) stands for Andy is happy
• If L stands for loves and B stands for Beth,
  then L(A,B) stands for Andy loves Beth.

103
Skill 4 the turn this logic statement into
English question

• You need to realise that a letter inside the
  brackets of a predicate may well be a variable,
  standing for something vague like something.

104
Skill 4 the turn this logic statement into
English question

• Provided you know all this, this sort of question
  is easy.
• You just write a framework for the logic
  connective, and slot phrases representing the
  predicates into it.

105
Skill 4 the turn this logic statement into
English question

• If H stands for happy and A stands for Andy,
  and B stands for Beth, L stands for loves and
  R stands for rich, and C stands for clever,
  what does
• R(A) ? C(B) ? L(B, A) stand for?
• The logic symbols tell you that it will be
• if and then
• The predicates tell you what to put into the
  gaps
• if Andy is rich and Beth is clever then Beth
  loves Andy.