Lecture 11 Critical thinking about psychological research Flashcards
twee voorbeelden van “f you leave out enough, everything can become a beautiful story”
- Publication bias, file drawer problem
- Unspecified predictions, hidden nsustainable assumptions in theory
Half of publications in 8 major psychology
journals (1985-2013) that involve NHST contain at least 1 error in reported p-values.
- 1 in 8 contained a “grossly inconsistent p-value that may have affected the statistical conclusion”.
- Those gross inconsistencies were more likely when significant vs non-significant results were reported
researchers degrees of freedom
- Which research area, which theory, which
hypotheses? - How many dependent variables, how many
conditions? - What measurement procedure?
- How many participants?
- What analyses? What outliers?
- What is an effect? What is a relevant effect?
- What can you conclude from the analyses?
- What can you conclude from the investigations?
issues with robustness =
when researchers that use the same data, find different effects.
only 49% of the papers published could be reproduced
oke
waardoor komen die researcher degrees of freedom
door differences in robustness.
large researchers degree of freedom betekent
hogere variation
lagere robustness
lagere reliability
hoe gaat het ideale process van wetenschap
author writes research -> editor decides who should review -> editor sends to experts in area -> experts review etc
maar wat zien we helaas bij peer reviewers
mensen beoordelen significante resultaten als beter uitgevoerd, dan geen significante resultaten (hier is veel meer kritiek op)
Goals of science do not always go hand
in hand with the goals of the scientist
- Quantity of (frequently quoted) publications essential for further careers
- The problem is that the pursuit of truthful/robust and interpretable results in the current system does not always lead to publications
file drawer effect =
in science many results remain unpublished, especially negative ones.
Too much emphasis on new, surprising, findings is problematic:
- We think too quickly that a published positive result is a full-fledged phenomenon.
- Counterintuitive findings are looked at more, hoewel zij een lagere prior probability hebben
- Small and noisy samples
- Popular media will highlight catchy findings
als de prior probability laag is, is rejecting the H0…
minder informatief
kleiner sample =
kleinere power = minder informatief om H0 te rejecten
type 1 error rate staat gelijk aan
alpha
power is hetzelfde als
1 - B
wat is B
type 2 error/false negative
wat is een correcte true negative
1-a
dus alles op een rijtje: formules in het vierkant van links boven naar rechtsonder
type 1 error/a, power/1-B, correct true negative/1-a, type 2 error/1-B
hoe komt publication and reporting bias tot stand
- study publication bias
- outcome reporting bias
- spin
- citation bias
study publication bias =
trials zonder resultaten worden niet gepubliceerd
outcome reporting bias =
zelfs als de studie wel wordt gepubliceerd, worden de dingen zonder resultaat niet gepubliceerd in de final paper
spin=
researchers beschrijven het alsof iets heel significant en met veel effect is
citation bias =
dingen die werken hebben een hogere kans om geciteerd te wordne.