Week 5

Question 1

Conditional probability

Answer 1

the probability of one event occurring given that another condition is true

Question 2

P(a|b)

Answer 2

probability of a given b

Question 3

P(b|a)

Answer 3

probability of b given a

Question 4

prior probability

Answer 4

probability of it happening before you see the outcome

Question 5

posterior probability

Answer 5

probability of it happening/obtained after evidence is collected

Question 6

sensitivity

Answer 6

probability of a true positive result

Question 7

specificity

Answer 7

probability of a true negative result

Question 8

Fallacy of transposed conditional

Answer 8

flipping around the conditions in the probability statement
we have a intuitive but incorrect tendency to think we know the probability of condition B given point A when we have been presented with a conditional probability (probability of condition A given point B)

Question 9

low prior probability

Answer 9

low posterior probability

Question 10

high prior probability

Answer 10

high posterior

Question 11

p-value

Answer 11

conditional probability
probability of an event (observing data like ours) given a condition (null hypothesis is true)

Question 12

not all hypothesis

Answer 12

are equally plausible

Question 13

to evaluate plausibility

Answer 13

consider whether there is strong theoretical basis for the hypothesis, and whether there’s plausible mechanisms by which a hypothesis can be true

Question 14

what do we need to consider when determining the likelihood of b?

Answer 14

the prior probability of b being true

Question 15

how is a statistically significant outcome more convincing?

Answer 15

If the prior probability of the hypothesis is high rather than low

Question 16

Bem 2011

Answer 16

claimed to find evidence that information can travel back in time to affect our cognition and emotion

An implausible hypothesis that can’t possibly work and the effects have been difficult to replicate

Question 17

what shouldn’t p values be the only thing used for?

Answer 17

evidence as to whether to accept or reject a hypothesis

Question 18

sniff test

Answer 18

is the effect strong?
does it generalise to other populations? other situations?
do other researchers find these results?

Question 19

what could be alternative explanations?

Answer 19

experimental error
inappropriate methods or analysis techniques

Question 20

Straightforward replication

Answer 20

Identical copy of a previous study in order to see if the studies findings are valid and reliable

Question 21

Different participant population replication

Answer 21

Do these findings extend to other populations?

Question 22

Replications with different experimenters

Answer 22

These to less bias from preset ideas that experimentors may hold

Question 23

Previous studies may be carried out a long time ago

Answer 23

replicate to see if results are still relevant

Question 24

“good science”

Answer 24

accurate and reliable findings if replicated in a separate study

Question 25

Psychology and complexity of human behaviour make replications hard

Answer 25

large variability

Question 26

2015

Answer 26

replications of 100 psychology studies, only 39 were replicated

Question 27

questionable research practises (QRP)

Answer 27

Due to publication bias pressure to publish significant findings

Question 28

Simmons et al

Answer 28

Research question: does listening to children songs induce age contrast making people feel older?
2 songs were compared
People fell older after listening to the child song compared to the control p=.033 showing an age contrast effect

However, the actual study had three conditions/songs, older age contrast
Multiple questions asked, 10 in total
None of this was mentioned in the report

Question 29

issues with QRP

Answer 29

Make replications difficult
False positives are far more likely leading to pointless further studies and in effective treatment or policies
The field of psychology and it’s credibilities questioned

Question 30

4 common QRPs ‘degrees of freedom’

Answer 30

1. observing among DV 66.5%
2. choosing sample size
3. using covariates
4. reporting subsets of experimental conditions

Question 31

why use QRPs?

Answer 31

Pressure to publish significant findings
Ambiguity about decisions such as the exclusion of outliers
Confirmation bias such as preset ideas

Question 32

Lindsay 2015 troubling trio to help identify QRPs

Answer 32

1. low statistical power
2. surprising results
3. p value only slightly less than .05

Question 33

tackling QRPs

Answer 33

pre-registration of studies - writing down your hypothesis, study design, and analysis the plan before you collect any data
replication of ones one findings - reliability
open access data - allowing other researchers access to everything allows them to reproduce analyses, check analyses and conduct additional analyses
reduce publication bias against null findings
registered reports - methods and analysis is peer-reviewed before study is conducted

Question 34

individual differences to measure and control

Answer 34

personality
experience
physiological state
psychological state
genetics

Question 35

enviromental influences to control

Answer 35

temperature
context
lighting
time of day
social influence

Question 36

too much control

Answer 36

lowers ecological validity - findings don’t appear in real life

Question 37

questionable research practises

Answer 37

there are lots of decisions to make as a researcher about how best to conduct studies and analyse our data
the flexibility leaves room for QRPs to appear, we can make little changes to our study or analysis to make data ‘neater’

Question 38

Common QRPs

Answer 38

collecting data from more participants and then checking the results again
cherry-picking particular comparisons that “work” and discarding those that don’t
adding or removing ‘covariates’
running lots of studies and only reporting those that “work”
deciding which “outliers” to discard after looking at the data

Question 39

p-hacking

Answer 39

exploiting, perhaps unconsciously, researcher degrees of freedom until p<.05

Question 40

open science

Answer 40

open data
open source
open educational resources
open methodology
open access
open peer review