ARMS Modulen – Aantekeningen
Inhoud
Module 3 – Justify your Sample .............................................................................................................. 2
Lecture 1 – 18-12-2023 ....................................................................................................................... 2
Grasple – Power, Error Terms, Effect Sizes, Sample Sizes .................................................................... 3
Grasple – Sample Size Justifications .................................................................................................... 5
Artikel: Sample Size Justification – Lakens .......................................................................................... 6
Abstract ........................................................................................................................................... 6
Summary ......................................................................................................................................... 6
Lecture 2 – 8-1-2024 ........................................................................................................................... 8
Module 6 – Non-Parametric Testing and Single-Case Studies .............................................................. 12
Lecture 1 – 16-1-2024 ....................................................................................................................... 12
Example 1 – motor intervention therapy (MIT) ............................................................................ 12
Example 2 – visual discomfort in people with Complex Regional Pain Syndrome (CRPS) or
fibromyalgia (widespread pain) .................................................................................................... 20
Example 3 - visuospatial neglect after stroke................................................................................ 21
Example 4 – visuospatial neglect after stroke ............................................................................... 24
Practice Practical 1 ............................................................................................................................ 29
Lecture 2 – 22-1-2024 ....................................................................................................................... 30
1
,Module 3 – Justify your Sample
https://rpsychologist.com/d3/nhst/
Lecture 1 – 18-12-2023
Power = the probability of finding a significant result when there is an effect
Approaches
- Measure entire population (neat if possible)
- Resource constraints (try your best given situation)
- No justification (undesirable)
- Heuristics (probably bad)
Interdependency: if we know the sample size and what error levels we are willing to accept (alpha
and beta), we know how large of a sample we need.
2
,Grasple – Power, Error Terms, Effect Sizes, Sample Sizes
z-test = test to see whether there is a difference between the sample and the population or between
two samples
➔ Significantie is onwenselijk
➔ Rood: false positive (alpha)
➔ Donkerblauw: false negatives (beta)
➔ Lichtblauw: power (true positive) (1-beta)
➔ Wit: true negative (1-alpha)
Alpha klein → power klein (beta)
Grote sample size → narrow distribution (omdat dan de extreme waarden minder uitmaken)
Critical value/(critical error rate/alpha = kritische afkapwaarde
More participants → more power
➔
➔
o Narrower distribution
o Pieken op dezelfde plek
Effect size larger → means of distributions (pieken) further apart
➔ Impliceert groter verschil → dus groter verschil in m
➔ Power groter
3
, One tailed test
➔
➔
➔ One tailed test → richting → kritische waarde aan één kant → kritische waarde kleiner →
kleinere power
➔ Two tailed test → geen roichtinjg → kritische waarden aan twee kanten → klritische waarde
groter → grotere power
4
Inhoud
Module 3 – Justify your Sample .............................................................................................................. 2
Lecture 1 – 18-12-2023 ....................................................................................................................... 2
Grasple – Power, Error Terms, Effect Sizes, Sample Sizes .................................................................... 3
Grasple – Sample Size Justifications .................................................................................................... 5
Artikel: Sample Size Justification – Lakens .......................................................................................... 6
Abstract ........................................................................................................................................... 6
Summary ......................................................................................................................................... 6
Lecture 2 – 8-1-2024 ........................................................................................................................... 8
Module 6 – Non-Parametric Testing and Single-Case Studies .............................................................. 12
Lecture 1 – 16-1-2024 ....................................................................................................................... 12
Example 1 – motor intervention therapy (MIT) ............................................................................ 12
Example 2 – visual discomfort in people with Complex Regional Pain Syndrome (CRPS) or
fibromyalgia (widespread pain) .................................................................................................... 20
Example 3 - visuospatial neglect after stroke................................................................................ 21
Example 4 – visuospatial neglect after stroke ............................................................................... 24
Practice Practical 1 ............................................................................................................................ 29
Lecture 2 – 22-1-2024 ....................................................................................................................... 30
1
,Module 3 – Justify your Sample
https://rpsychologist.com/d3/nhst/
Lecture 1 – 18-12-2023
Power = the probability of finding a significant result when there is an effect
Approaches
- Measure entire population (neat if possible)
- Resource constraints (try your best given situation)
- No justification (undesirable)
- Heuristics (probably bad)
Interdependency: if we know the sample size and what error levels we are willing to accept (alpha
and beta), we know how large of a sample we need.
2
,Grasple – Power, Error Terms, Effect Sizes, Sample Sizes
z-test = test to see whether there is a difference between the sample and the population or between
two samples
➔ Significantie is onwenselijk
➔ Rood: false positive (alpha)
➔ Donkerblauw: false negatives (beta)
➔ Lichtblauw: power (true positive) (1-beta)
➔ Wit: true negative (1-alpha)
Alpha klein → power klein (beta)
Grote sample size → narrow distribution (omdat dan de extreme waarden minder uitmaken)
Critical value/(critical error rate/alpha = kritische afkapwaarde
More participants → more power
➔
➔
o Narrower distribution
o Pieken op dezelfde plek
Effect size larger → means of distributions (pieken) further apart
➔ Impliceert groter verschil → dus groter verschil in m
➔ Power groter
3
, One tailed test
➔
➔
➔ One tailed test → richting → kritische waarde aan één kant → kritische waarde kleiner →
kleinere power
➔ Two tailed test → geen roichtinjg → kritische waarden aan twee kanten → klritische waarde
groter → grotere power
4
