research methods Flashcards
when to use mann whitney u
independent groups
ordinal data
what does N stand for in mann whitney u
N1 - sample size of group 1
N2 - sample size of group 2
what does R1 stand for in mann whitney U
sum of ranks for group one/ the largest group
how to calculate mann whitney U
- rank the scores of the entire sample together
- put back into separate groups and add up rank total
- larger = group 1
- plug into equation
how to calculate U for the other group
Ub = (N1 x N2) - U
what makes mann whitney u significant
less than or equal to the critical value
what to include in hypothesis writing
- null or alternate (significant or not)
- operationalise IV (what changes)
- operationalise DV (how it’s measured)
- context
strengths and weaknesses
opportunity sampling
strengths: convenient, fast, cheap
weaknesses: not representative or random - sampling bias
✅❌
self selected sampling
✅ willing participants, can target specific people, easy and fast
❌ response bias (similar people) time consuming
✅❌
random sampling (database)
✅ representational, equal chance of selection
❌ restricted access to databases, not as replicable, not everyone is in a database
✅❌
snowball sampling
✅ find specific individuals
❌ time consuming, share common traits do not representative
✅❌
stratified sampling (maths to work out subcategories)
✅ representative
❌ smaller samples and time consuming
order of harvard referencing
last name first name
date
title
publisher
publisher place
page number
bps guidelines for ethics (7)
consent
debrief
right to withdrawal
protection from harm/distress
deception
confidentiality
responsibility
✅❌
questionnaires
✅ reliable (replicable and standardised), easy to administer, anonymous - willing to reveal, focused
❌ social desirability bias, sample bias (certain types of people)
social desirability bias definition
answering in a way we believe is socially acceptable or desirable
demand characteristics definition and examples x2
clues given to participants about aim of study - causing them to change behaviour
examples: leading questions, overt observations
✅❌
structured interviews
✅ comparable (predictable and rigid) easy to administer
❌ social desirability bias, restricted data collection
✅❌
semi/unstructured interviews
✅ more qualitative data and more detail, flexible
❌ required skilled interviewers, low inter rated reliability, harder to compare, more susceptible to interviewer bias (their expectations)
✅❌
self report
✅ qualitative and quantitative data, easy analysis, convenient, ethical
❌ social desirability bias, low response rate, can be up to interpretation
split half technique
measuring consistency by asking same question twice (flipped)
increases reliability