1.2 Quantitative Research - The Experiment Flashcards
What must you do to get the most accurate results?
In order to get the most accurate results, you must isolate IV and manipulate it so nothing else changes
What is a confounding variable?
any unwanted variables that may influence the dependent variable (distort relationship between IV and DV)
What are confounding variables linked to?
linked to/contribute to bias
What needs to be done to confounding variables to reduce the chance of them affecting the results?
Need to be either completely eliminated or kept constant in all groups so they do not affect comparison
What does the experiment aim to do?
Experiment aims to discover universal laws of behaviour applicable to large groups of people across a variety of situations
What is the target popualtion?
group of people to which the findings of the study are expected to be generalised
What is representativeness?
a key property of a sample ensures that info obtained from the sample can be generalised to the target population
Is there a quantitative way to establish representativeness?
NO
How do researchers know which characteristics they want in a sample?
Researchers decide what characteristics are essential
Done on basis of prior knowledge, theories and studies
How is the sampling technique decided upon?
available resources
aim of the research
nature of the target population
What is an advantage of random sampling?
The ideal approach to make a sample representative
Allows all random characteristics to be sampled, making results easily generalisable and every member of the target population has an equal chance of becoming part of the sample
What is a disadvantage of random sampling?
Not always possible for practical reasons:
E.g if based in Europe can not get a sample of every race of teenager from every country
In this case, you either believe that cross-cultural differences are not essential or narrow down your target population
How does stratified sampling work?
More theory-driven
First, decide characteristics that the sample has to reflect
Study distribution of this characteristic in target population e.g use statistical data
Recruit participants in the same proportion as they are in population
How does convenience sampling work?
Recruit participants that are easily available
What are the advantages of convenience sampling?
Easy choice when financial resources and time are limited
Certain studies do not need cross-cultural samples etc
Useful when the wide generalisation of findings is not the primary goal of research e.g only doing an exploratory study and only want to check hypothesis or testing someone else’s theory
What is a disadvantage of convenience sampling?
lack of representativeness
What is self-selected sampling?
Refers to recruiting volunteers
e.g advertising in a newspaper
What is an advantage of self-selected sampling?
Quick and easy + wide coverage
What is a disadvantage of self-selected sampling?
Limit is lack of representativeness e.g people may be motivated than the general population or looking for incentives
What does experimental design mean?
the organisation of groups and conditions in an experiment
What are the 3 main types of quantitative experimental designs?
- independent measures design
- matched pairs design
- repeated measures design
What is the general process of independent measures design?
Involves random allocation of participants into groups and a comparison between these groups.
Randomly assign people to groups i.e control and experimental and manipulate experimental conditions, then compare DV
Why is random allocation used in independent measures design?
The rationale behind random group allocation is that all potential confounding variables cancel each other out
The larger the group higher the chance of the groups being equivalent
When is an experiment said to follow an independent measures design?
The experiment follows an independent measures design when the IV is manipulated by randomly allocating participants into groups, allowing us to assume that groups are equivalent, so whatever difference we observe is a result of the experimental manipulation