Honours SeminarHonours Seminar

Lecture 3: Critical ThinkingLecture 3: Critical Thinking

Scientific ReasoningScientific Reasoning FalsifiableFalsifiable

Why am I not necessarily right?Why am I not necessarily right? How often does someone argue against How often does someone argue against

themselves?themselves? LogicLogic

People do not think logicallyPeople do not think logically Comprehensiveness: Comprehensiveness:

Does it account for all the data, e.g. 110 year old Does it account for all the data, e.g. 110 year old smoker, thus smoking does not cause problemssmoker, thus smoking does not cause problems

Honesty – are we objectiveHonesty – are we objective E.g., international students go to the library E.g., international students go to the library

togethertogether

More on Scientific More on Scientific ReasoningReasoning

ReplicabilityReplicability True effects have been systematically True effects have been systematically

replicatedreplicated SufficiencySufficiency

Burden of proof is on the claimant, e.g., drugsBurden of proof is on the claimant, e.g., drugs Extraordinary claims neede extraordinary Extraordinary claims neede extraordinary

evidenceevidence E.g., crop circlesE.g., crop circles

General contrariness: Some people want General contrariness: Some people want to argueanythingto argueanything

Strength of prevailing views of scienceStrength of prevailing views of science

Antiscientific beliefsAntiscientific beliefs Post-modernismPost-modernism

What is the colour Red?What is the colour Red? There is no such thing as a learning disabilityThere is no such thing as a learning disability

““What works is different for everybody”What works is different for everybody” Bushmills cures sore throatsBushmills cures sore throats

Probabilities are irrelevant individualsProbabilities are irrelevant individuals E.g., runner drops dead. People say “see, why E.g., runner drops dead. People say “see, why

run”run” Science itself is badScience itself is bad

E.g., testing in schoolsE.g., testing in schools

Critical thinkingCritical thinking

Tries to function independently of Tries to function independently of preconceived notions of how the world preconceived notions of how the world functionsfunctions

Focuses on the simplest explanation of Focuses on the simplest explanation of eventsevents

Thinks of ways in which a conclusion may Thinks of ways in which a conclusion may be at faultbe at fault

Tries to think of ways to strengthen Tries to think of ways to strengthen research designs to isolate an dependent research designs to isolate an dependent variable variable

Trends in research Trends in research designsdesigns

Observational researchObservational research Participant observationParticipant observation Correlational researchCorrelational research Quasi-experimental researchQuasi-experimental research Experimental researchExperimental research

Blind, Double-BlindBlind, Double-Blind

Example: You wish to show that caffeine causes accelerated motor behaviour in students

Correlational research Correlational research designsdesigns

Direction of causalityDirection of causality Example: A soccer ball is kicked. It Example: A soccer ball is kicked. It

goes up a certain height and is in the goes up a certain height and is in the air a certain length of time. Does the air a certain length of time. Does the height cause the time, or does the time height cause the time, or does the time cause the height?cause the height?

A causes BA causes B B causes AB causes A C causes A and BC causes A and B

The importance of The importance of experimentsexperiments

Random assignment should equate your Random assignment should equate your groups on individual differencesgroups on individual differences

Self selection to groups means that Self selection to groups means that non-random influences could account non-random influences could account for the differences between the groupsfor the differences between the groups

There are other problems with There are other problems with experiments:experiments: Diffusion of your treatmentDiffusion of your treatment ““Hypothesis guessing”Hypothesis guessing” Attrition can result in loss of randomisationAttrition can result in loss of randomisation

Construct validity of Construct validity of measuresmeasures

What are you measuring?What are you measuring? Are you sure you are measuring what you Are you sure you are measuring what you

are measuring?are measuring? Example: Example:

Obese and non-obese people are in a waiting Obese and non-obese people are in a waiting roomroom

Shelled and non-shelled peanuts are availableShelled and non-shelled peanuts are available Obese people eat more non-shelled peanutsObese people eat more non-shelled peanuts How do you interpret these results?How do you interpret these results? Can you offer an alternative explanation for Can you offer an alternative explanation for

these resultsthese results

External validityExternal validity

Results may not generalise to other Results may not generalise to other samples or populationssamples or populations

Why? What non-random effects exist Why? What non-random effects exist in your sample that may differ from in your sample that may differ from others?others? Example: A study of reading conducted Example: A study of reading conducted

in Nova Scotia. Will it generalise to other in Nova Scotia. Will it generalise to other provinces? Why or why not?provinces? Why or why not?

Psychology students are recruited into a Psychology students are recruited into a study to show that family disruption is study to show that family disruption is related to well-being at university.related to well-being at university.

Newspaper task: Identify a Newspaper task: Identify a testable hypothesis and testable hypothesis and translate the research translate the research

questions into an questions into an experimental research experimental research

designdesign Observational researchObservational research Participant observationParticipant observation Quasi-experimental researchQuasi-experimental research Experimental researchExperimental research

Blind, Double-BlindBlind, Double-Blind

HypothesesHypotheses Sarah, Kelly, Tina, Kate: ExperimentalSarah, Kelly, Tina, Kate: Experimental

Does an Emergency Response Program work, Does an Emergency Response Program work, compare 3 kinds of schools randomly selected compare 3 kinds of schools randomly selected

Megan, Nadia, Julia, Andrea: Quasi-Megan, Nadia, Julia, Andrea: Quasi-experimentalexperimental Adjustment of golfers to loss of parent vs. loss of Adjustment of golfers to loss of parent vs. loss of

spousespouse Practice time, play, scores, Practice time, play, scores,

Xian, Marielle, Kara, Susan: ObservationalXian, Marielle, Kara, Susan: Observational Dawson College: Trauma of the school shooting Dawson College: Trauma of the school shooting

will demotivate studentswill demotivate students Emily, Beth, Hollie: CorrelationalEmily, Beth, Hollie: Correlational

Personality type and reading you horoscope (e.g., Personality type and reading you horoscope (e.g., suggestability)suggestability)