Unit 2 Flashcards
(25 cards)
What is internal validity?
The ability to draw conclusion about casual relationships from our data (e.g. does x cause y?)
What is external validity?
Extent to which the results can be generalised to other populations and settings (e.g. Can these results be applied to a different sample?)
What is confounding variables?
Something that affects some participants but not others, having negative consequences for validity
What is directional hypothesis?
Saying that there will be a specific difference
What is non-directional hypothesis?
Saying that there will be a difference
What is an independent variable?
A factor that is changed or manipulated
What is a dependant variable
The factor measured
What is an aim?
A general statement about the purpose of the investigation
What is a hypothesis?
The expected outcome of an experiment
What is a laboratory experiment?
strengths + weaknesses
Experiments conducted in highly controlled environments (not always a lab, could be a place such as a classroom)
Strengths
- Makes the results reliable
- Makes replication more possible
Weaknesses
- Lacks ecological validity
- Demand characteristics
What is a field experiment?
Strengths + weaknesses
Where the IV is manipulated in a natural, everyday setting
Strengths
- High ecological validity
- Less demand characteristics
Weaknesses
- Precise replication not possible
- Participants cannot give informed consent
Quasi-experiment
Strength + weakness
A naturally occurring IV
Strength
1. Reliable
Weakness
1. Participants cannot be randomly allocated
What is a target population?
Who you want to generalise to
What is a sampling frame?
The population you can get access to
What is random sampling?
Strength + weakness
Completely random-every member of the population has an equal chance of being selected
Strength
1.Provides the best chance of an unbiased sample
Weakness
1. Can be time consuming
What is opportunity sampling?
Strengths + weaknesses
Selecting people that are available at the time
Strength
- Quick
- Convient
Weaknesses
1. Bias by the researcher as they chose people who look friendly/helpful
What is systematic sampling?
Strengths + Weaknesses
Choosing participants in an orderly way (every nth participant)
Strength
1. Should provide a representative sample
Weakness
1.Requires a lot of time, effort and money
What is snowball sampling
Strengths + Weaknesses
A sample in which the initial participants are asked to identify additional members of a population
Strengths
1. Enables researcher to locate groups of people who are difficult to access such as drug addicts
Weaknesses
1. Unlikely to be representative or generalisable
What os self selected sampling
Strengths + Weaknesses
Members of the population select themselves by volunteering and then the researcher select from those or use all of them
Strengths
- Has willings participants (less likely to drop out or not give consent)
- No researcher bias
Weaknesses
- More likely to be unrepresentative
- Likely to get people who have extreme views
What is co-variables?
Variables in a correlation, must be continuous and related
What is extraneous variables?
Something unwanted or unexpected that might affect the dependant variable
What is Nominal data?
Used when data belong to distinct categories (e.g. male and female)
What is interval data?
Data that can be measured in equal intervals
What is ratio data?
Data with an absolute zero e.g. reaction time
