L1- Experimental Methods Flashcards
What is the independent variable?
- variable researcher manipulates to determine its effect on the dependant variable
- divided into levels called experimental conditions
What is the control condition?
Provides a standard against which experimental conditions can be compared
What is the dependant variable?
The variable that is being measured
What are extraneous variables?
Variables other than the IV that COULD affect the DV
What are confounding variables?
Variables other than the IV that HAVE affected the DV (light, noise)
How do you operationalise?
Define and measure
What are laboratory experiments?
- experiment carried out in controlled environment allowing for high control over IV and eliminate EV to minimise impact on results
- observe and measure change in DV caused by manipulation of IV
- participants randomly allocated
Advantages of lab experiements
+ high control- easy to control EV and prevent them from becoming confounding variables
+ can manipulate IV to establish cause and effect between IV and DV
+ easily repeated to see if similar results obtained- if so then reliable
Disadvantages of lab experiments
- demand characteristics- behave more positively (social desirability bias), data invalid
- high control= lacks mundane realism and ecological validity
What are field experiments?
- experiment carried out in natural setting
- IV still manipulated to see effect on DV
-e.g. observe people in street
Advantages of field experiments
+ more mundane realism and ecological validity than lab
+ cause and effect between IV and DV can be established as IV is manipulated
+ less chance of demand characteristics- not even aware taking part, behave naturally, valid data
Disadvantages of field experiments
- less control over EV compared to lab- effect on DV may be caused by EV not IV, invalid data a
- less control over sample- sample may not be representative
- difficult to repeat- unreliable
- ethical issues- lack of consent
What are Natural experiments?
- sees effect of naturally occurring IV on DV
Advantages of natural experiments
- high mundane realism and ecological validity compared to lab
- useful when impossible or unethical to manipulate IV in lab/field
Disadvantages of natural experiments
- low control over EV compared to lab
- difficult to repeat, unreliable
- difficult to determine cause and effect due to low control
What are quasi experiments?
- naturally occurring IV which is a difference between people that already exists (gender, age)
-examined effect of this IV on DV - take place in lab
Advantages of Quasi experiments
- high control, effects of EV minimised, more likely DV affected by IV not EV
- easy to replicate due to strict control
Disadvantages of Quasi experiment
- lacks ecological validity- artificial setting
- demand characteristics- guess aim of experiment and response accordingly, data invalid
Types of experiments
-lab
-field
-natural
-quasi
What are the experimental conditions?
- when the IV is divided into levels
What is reliablity?
Reliability is a measure of whether something stays the same, i.e. is consistent.
What are demand characteristics?
Demand characteristics occur when the participants try to make sense of the research and act accordingly to support the aim of the research- validity
What is social desirability bias?
Participants’ behaviour is distorted as they modify this in order to be seen in a positive light.
Mundane realism
describes the degree to which the materials and procedures involved in an experiment are similar to events that occur in the real world
What is ecological validity?
, a measure of how test performance predicts behaviours in real-world settings
What is validity?
- the extent to which a research technique actually measures the behaviour it is claimed to measure.
-( For example, a relationship questionnaire is not a valid measure of aggression)
