Are you a student at risk?

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Are you a student at risk?

• The first tutorial quiz has been available on
  webCT since this Monday morning
• 14 questions, unlimited attempts, worth marks in
  this course, closes this Sunday
• Have you done it?
• If not, why not?
• Information on the quizzes, manual p.11-12
• Find the actual quiz on webCT Assessmentgt
  Tutorial Quizzes

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http//www.senseaboutscience.org.uk/index.php/site
/project/71/
10/10 Homeopaths prescribe homeopathic protection
for malaria! (UK newspaper studies)
http//www.dailymail.co.uk/news/article-395568/Don
t-rely-homeopathy-beat-malaria-doctors-warn.html
http//news.bbc.co.uk/1/hi/uk/5178488.stm
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Science and StatisticsLecture 2The power of a
name Measurement and constructs

• Dr Caleb Owens
• caleb.owens_at_sydney.edu.au
• Consultation Wednesdays 9-10am

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What is the difference between science and
technology?

• Technology is a craft
• Science is an understanding
• Is technology just applied science ?

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Scientific constructs and concepts

• Energy
• Heat energy
• Kinetic energy
• Work
• Structures
• atom
• molecule
• bonds / forces
• Process
• Reaction
• Conduction
• Gravity
• Time
• Life
• Ecosystem
• Food chain
• DNA
• cell

• Approximations of reality
• Descriptions of reality
• Concepts we try to measure
• Concepts we use to make predictions

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Some psychological concepts and constructs

• Memory
• Intelligence
• Personality
• Consciousness / Self-control
• Attitude
• Mood
• Arousal
• Motivation

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Variables

• Anything that varies.
• The opposite of a variable is a constant
• It depends on the experimental context
• Is sex a variable in an all female study on
  body image?
• Is sex a variable in a study of differences
  between the map reading ability of males and
  females?

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Independent Dependent Variables
Independent Variable
Dependent Variable

• Presumed Cause
• Antecedent Cause
• Stimulus Variable

• Behaviour of Interest
• Response Variable

Manipulated by experimenter
Measured by experimenter
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• Independent variables are manipulated by an
  experimenter
• Dependent variables are measured by an
  experimenter
• Extraneous variables are controlled by an
  experimenter (kept constant) or allowed to vary
  randomly

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Independent Dependent Variables

• Is childrens intelligence affected by watching
  television?
• Does marijuana use lead to schizophrenia?
• Is there a relationship between your personality
  and your health?

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Defining Variables

• Conceptual Definitions
• Define variables in terms of other concepts
• E.g. Stress a state of strain, whether physical
  or psychological
• Sometimes called constructs
• Are they real/reliable? (reification)
• Theoretical constructs are unobservable, so how
  can we measure them? (operational definition)

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Reification

• The treatment of an analytic or abstract
  relationship as though it were a concrete entity

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Natural

• Robert T Carroll on natural (from
  http//www.skepdic.com/natural.html)
• Something present in or produced by nature is
  natural, such as an earthquake or typhoon, or a
  poisonous mushroom.
• Just because something is natural does not mean
  that it is good, safe or healthy. Herbs are
  natural but they are also drugs when used in the
  diagnosis, treatment, or prevention of a disease.
  The chemicals which comprise synthetic drugs are
  natural. St. John's Wort (Hypericum perforatum)
  is natural, but it is a drug. Why do some people
  say that they prefer St. John's Wort to drugs for
  depression? If someone said that he preferred
  Irish whiskey to alcohol, we'd think he was
  confused.
• Other terms that we assume have a specific
  meaning organic, free range, dolphin friendly,
  chemical free, anti-oxidant
• Choice magazine and the ACC often review the
  commercial use of such terms

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Luck

• When good or bad things happen to us in a pattern
  we say we are lucky or unlucky
• As an adjective this is fine
• However some people believe luck is a thing or a
  cause, not merely a result (or a description of
  how things have turned out)
• Psychologists study peoples understanding of
  luck as a factor in gambling behaviour, but
  luck as a superstitious concept is not studied.

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Vitalistic thinking

• Common in young children
• mountains are for climbing
• lions are for walking around and being in zoos
• Some adults think this way
• e.g. When we have a cut finger what makes it get
  better?
• Our cut finger uses energy to get better / our
  cut finger wants to get better
• Finger tissue and veins start growing / the wound
  is purified of destroyed cells

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Energy

• Vitalistic Healing, living, purifying, dying,
  growing, withering, hereditary, in motion,
  poisonous, an emotion, good, bad, masculine and
  feminine
• Scientific Energy can manifest itself as heat,
  energy can be a physical capacity for doing work

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Adults who use vitalistic thinking are more
likely to believe in

• Paranormal agents
• Ghosts
• Spirits
• God
• Luck
• Telepathy
• Spiritualism
• Precognition
• lunar effects
• Amulets
• crystal power
• Witches
• astrology

• Chiropractic
• Acupuncture
• Homeopathy
• Natural remedies
• Megadoses of vitamins
• Magnetic field treatments
• Kirilian photography
• Stone therapy
• Reiki
• reflexology

Lindeman Saher (2007) British Journal of
Psychology, 98, 33-44.
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Vitalism around the world

• China CHI / QI
• Japan Ki
• Indian PRANA
• Western Europe (Homeopathy) SUBTLE ENERGY
• Western Europe ANIMAL SPIRITS
• The flow of animal spirits carried our thoughts
• But after 1857 vitalism begins to disappear in
  the West
• These metaphysical concepts are the fairies in
  my backyard. Can they ever be measured?

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Ki master video

• A Japanese Ki master believes he can knock out
  people only with the power of ki
• He is seen knocking out an entire room full of
  his disciples (who no doubt know what is expected
  of them)
• He puts an advertisement online for a 5000
  reward for anyone who can beat him with tragic
  consequences

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The pragmatic fallacy

• Something is true because (something else)
  works! i.e. an explanation or model for how an
  effect might happen is also right just because
  the effect is proven
• e.g. Chi is real because acupuncture works
• These are two separate questions
• Does acupuncture work? Why does it work?
• In psychology we know about many effects, but are
  not always sure of the explanation, theory or
  model behind these effects
• A good start is to use constructs which are
  useful, real and easily defined

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Evidence e.g. Acupuncture works!
Theory e.g. A invisible force call Chi flows
through our bodies and must be unblocked
Theory 2 e.g. The needles excite the
parasympathetic nervous system
Theory 3e.g. The placebo effect causes peace of
mind
Eliminate theories which use unfalsifiable
concepts
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Theory e.g. Talking about your childhood
unshackles the unconsciousness and allows
unfulfilled wishes to gain expression
Evidence e.g. Psychotherapy works!
Theory 2 e.g. Talking per se to a sympathetic
human makes you feel better!
Theory 3e.g. Cognitive behavioural therapy give
you skills and techniques to cope
Eliminate theories which use unfalsifiable
concepts
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Psychological concepts and constructs

• Memory
• Intelligence
• Personality
• Consciousness / Self-control
• Attitude
• Mood
• Arousal
• Motivation

• Notice how most cannot be directly observed
• Where do they come from?
• Are they useful?
• How do we define them?

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Defining Variables

• Operational Definitions
• Define in terms of the operations carried out in
  measuring or manipulating them
• E.g. we might measure motivation in a rat by
  looking at its rate of button pressing
• An objective procedure that others can replicate
  (for IVs and DVs).

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Operationalising Constructs
Construct (Comes from theory) Operational Definition (Can be observed)
Motivation Rate of button pressing
Memory Number of things recalled
Learning Decrease in time to solve puzzle
Personality Score on questionnaire
Arousal Heart rate, blood pressure
Attitude Number circled on a scale
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Two warnings about Operational Definitions

• Dont confuse the operational definition with the
  construct
• E.g. Intelligence is what intelligence tests
  measure.
• The operational definition might be a good or a
  bad way to observe the construct
• E.g. Is circling a number on a scale a good way
  to observe a persons attitude?
• Controversy over self-report as a measure of
  personality and attitude (e.g. prejudice)

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Categorical vs. Continuous

• Categorical variables
• Sometimes called qualitative
• Values of the variable fall into discrete classes
  (e.g. gender, favourite colour, country of birth)
• Continuous variables
• Sometimes called quantitative or scale
• Values of the variable can be anywhere within a
  range (e.g. age, weight, height, speed of driving)

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Scales of Measurement

• The categorical / continuous distinction can be
  broken down further into scale types

Categorical (Qualitative) Categorical (Qualitative) Continuous (Quantitative) Continuous (Quantitative)
Scales Nominal Ordinal Interval Ratio
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Nominal Scales

• Used for categorical (not continuous) data
• Numbers are arbitrary they act as labels, they
  are there instead of names (nominal)
• Numbers indicate
• sameness or difference
• Numbers dont indicate size or order

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Nominal Scales
Scale 1 Scale 2
Asian 1 Hispanic 7
Hispanic 2 Caucasian 1
Aboriginal 3 Asian 17
Caucasian 4 Aboriginal 42
Other 5 Other 45
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Ordinal Scales

• Used where numbers are ranked / ordered
• Numbers indicate
• Sameness or Difference
• More or less
• Numbers dont tell us anything more than order
• E.g. the difference between Titanic revenue and
  Return of the King revenue, may be much greater
  than the difference between return of the King
  Revenue and the gross for Dead Mans chest

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Ordinal Scales
Name World box office rank
Avatar 1
Titanic 2
Return of the King 3
Dead Mans Chest 4
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Interval Scales

• Used where numbers are separated by equal-sized
  intervals but have no meaningful or absolute
  zero.
• Numbers indicate
• Sameness or difference
• More or less
• Same or different intervals, greater or smaller
  intervals

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Interval Scales
Temperature (ºC)
0º
10º
15º
20º
100º
Temp. Difference
10º
5º
5º
80º
Order on differences
10º gt 5º
5º 5º
80º gt 5º
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The taller than Tom scale

• 0 same height as Tom Cruise
• 1 1cm taller
• The difference in TTT between Hugo and George,
  and George and Katie, is the same (10)
• BUT George is not twice as tall as Katie, and
  Hugo is not three times as tall as Katie

Name TTT
Hugo 30
Katie 10
George 20
Gimli 0
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Interval Scales
Name Amount more than Harry Potter 1
Avatar 1,637,296,346
Titanic 866,642,109
Return of the King 160,561,361
Dead Mans Chest 91,674,737
Harry Potter and the Sorcerers Stone took
968,657,891
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Ratio Scale

• Numbers indicate
• Sameness or difference
• More or less
• Same or different intervals, greater or smaller
  intervals
• Ratios, fractions
• Ratio Scales have an absolute zero point

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Ratio Scales

• Examples Time, length, weight, money
• 2km 7.3km 9.3km
• 100 kg is twice as heavy as 50 kg
• A 0 balance means you have no money! (but 0ºC
  does not mean there is no energy)

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Ratio Scales
Name World box office takings
Avatar 2,605,954,237
Titanic 1,835,300,000
Return of the King 1,129,219,252
Dead Mans Chest 1,060,332,628
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Summary

• Science is distinguished from technology by an
  understanding of the underlying mechanisms and
  processes
• Be cautious when dealing with concepts
• Are they real things
• Are they just adjectives or properties?
• Can they be defined in a useful way?
• The thing you measure does NOT equal the concept
  you want to talk about
• (The thing you measure can only, at best, reflect
  or approximate the thing you want to talk about)
• The kind of scale you use in research can limit
  the inferences you can draw

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Dont forget wikipedia for more!
From wikipedia http//en.wikipedia.org/wiki/Ratio
_scaleRatio_measurement