Research methods Flashcards
null hypothesis
suggests that there is no relationship between two variables
alternate/experimental hypothesis
prediction on what will happen in the experiment
random sampling
when each sample has an equal chance to get chosen
s: lack of bias, simple
W: gaining access to a large population is difficult
stratified sampling
the division of a population into smaller sub groups known as stratas
S: precise estimates for all subgroups
W: analysing the datasets is complex
volunteer sampling
individuals who have chosen to be involved
S: relatively convient and ethical
W: unrepresentative, bias
oppurtunity sampling
simply selectring those who are available at the time
S: quick, convenient, economical (most common type)
W: unrepresentative, bias from researchers
systematic sampling
creating a system to pick our sample
S: practical
W: doesn’t reduce bias the best
experimental designs
how participants are allocated to different groups in an experiment.
- independent groups, matched pairs, repeated measures
independent groups
different group of participants for each level of the IV
S: order effects are not a problem as the participants only do the experiment once
W: participant variables (can act as EVs)
repeated measures
All participants take part in all levels of the IV
S: No participant variables, fewer participants so less expensive
W: Order effects reduce validity
matched pairs
participants are matched based on key variables, or shared characteristics, relevant to the topic of the study. Then, one member of each pair is placed into the control group while the other is placed in the experimental group.
S: no order effects, fewer participants
W: takes time to match paticipants, doesn’t control all participant variables
participant variable
any characteristic or aspect of a participant’s background that could affect study results, even though it’s not the focus of an experiment
E.g. sex, gender identity, age, educational attainment, marital status, religious affiliation
order effects
refers to the well-documented phenomenon that different orders in which the questions are presented may influence respondents’ answers in a more or less systematic fashion.
Basically participants get bored and results reflect it.