psychology as science Flashcards
history of knwoledge acquisition
informatio centralised in libraries, hard to access
limited public access
information filtered through academic experts
now information on internet its widely academic
widepsread dissemination of misinformation
consequences of internet
need to be critical consumer evaluate information myself consult credible, reliable information services use primary sources experts publish peer reviewed journals
HMR hoax
1998 wakefield claimed children who had mmr vaccine developed autism
ignore high quality research showing no link
biased and uninformed media coverage
measles outbreak due to parents not getting vaccinated out of fear
how to obtain knowledge
authority figures:celebs, religious leaders, political leaders, consultants and senior academics
introspections and intuition: psychology is common sense
experience: personal or second hand
scientific method: key elements, objective measurements, refutation, reinterpretation
authority figures
abuse status to exploit
gwyneth paltrow fined $145,000 for unproven health claims
introspection and intuition
humans lack insight about how they function human reasoning is biased irrational judegments influenced by prejudices confirmation bias availability heuristic
illusory pattern detection
prone to seeing patterns in randomness eg faces in clouds
scientific method
theory generates hypothesis hypothesis leads to testable prediction obtain data that's used to test hypothesis interpret data used to create conclusion relate findings to hypothesis generate more hypotheses
characteristics of scientific method
not defined by subject matter
not defined by use of experimental method
not defined by obtaining qualitative data
defined by approach-rational, systematic, objective, careful
results open to scrutiny by skeptical others, potentially falsifiable, ideally reproducable
difference between science and pseudo science
science produces testable claims that are open to disproof
scientific claims must acknowledge all findings whether supportive or not
pseudo science uses evidence selectively to support belief ignores everything contradictory evidence
limitation to scientific method
restricted to testable questions not claims eg ‘god exists, but doesn’t reveal himself’
theory, hypothesis, predictions and data
theory: evidence based conceptual framework that tried to explain set of facts and observations, used to make testable predictions
hypothesis: proposed explanation derived from theory
prediction: scientific, testable prediction stemming from hypothesis
data: facts attempting to explain prove or disprove a theory
why do we quantify things
defining principle of science is measurement as can be objectively obtained
measurements must be reliable and valid
levels of measurement
nominal: numbers used as names, count how often each number occurs, frequencies of categories
ordinal: numbers used as ranks, attitude scales
interval: scale has equal intervals between points but no true zero point, IQ score, temperature
ratio: measurements made on scale with equal intervals and true zero point, reaction times/error scores
reliabilty
results msut be consistent and reproducible
a score = true score + error
error due to:natural performance variation (with/between variation), imprecision in defining and measuring psychological constructs (exactly defining aggression)
meaures of reliability
test retest
alternate forms
aplit half
inter scorer
factors affecting reliability
phenomenon itself (traits vs states) precision of measurement sample size (bigger > small) time between tests (shorter > longer) variability in performance (high > low) format of test (multiple choice > true/false) between individuals variability in scores (high > low)
replication crisis
causes: small sample sizes encourage flukes
straight replications are rare
file drawer problem: hard to get failed replications published
solutions: replications, meta analysis, converging operations
Nosek 2015
replicated 100 experimental and correlational studies from 3 prestigous journals
97% original studies had significant results
36% replications had significant results
combining original and replication results left 68% studies had statistically significant effects
validity
measure what its supposed to be measuring
measure can reliable but not valid
reliable but invalid: phrenology
gall and spurzheim
different parts of brain responsible for different mental faculties
highly developed faculties led to larger brain regions
larger brain regions reflected by bumps on skull
reliable as scientific but invalid as bumps no relation to brain
reliable but invalid: brain size
paul broca 1870s
292 male brains, 140 female brains
‘women on average less intelligent than men, small size brain depends on intellectual inferiority
measures of validity
face content criterion construct ecological/external
factors affecting validity
only influence on dependent variable is manipulation of independent variable
norms and standardisation
stratified random sampling
control group to compare against