Research Methods Flashcards
What are the four types of experiment?
Laboratory
Natural
Field
Quasi
Laboratory experiment
Takes place in a controlled environment within which the researcher manipulates the IV and records the effect on the DV
Whilst having strict controls of extraneous variables
Strength of a laboratory experiment
High internal validity meaning observed change in DV is due to change in the IV
Lab studies are easily replicated due to the use of standardised procedures and controls of extraneous variables
By holding all variables outside the IV and DV consistent researchers can be confident in establishing a cause and affect relationship between the changes and manipulation in the IV and the observed difference in the DV
Weaknesses of lab experiments
Lack ecological validity this means that findings cannot be applied to the real world
Tasks conducted in lab studies fail to reflect tasks performed in the real world situations as they are usually meaningless so lack mundane realism
Therefore, lacks external validity
Participants are also aware that in a study so they might show demand characteristics changing behaviour to match the aim
Field experiment
IV manipulated in a natural more every day setting
Changing location is an attempt to avoid the artificial nature of a lab experiment
E.g observation
Strengths of a field experiment
Higher ecological validity as PPTS behave more naturally and their normal environment making it more likely for any behaviour observed in a field experiment
Can apply to the real world as tasks used are more likely to have mundane realism so will reflect the daily tasks of what the participants normally do
Unaware that in an experiment so there are no demand characteristics
Weaknesses of a field experiment
Unaware of being studied means that participants did not give consent so this is ethically wrong as it is an invasion of privacy
Difficult to replicate
Lack of controls over possible extraneous variables that could influence the measurement of the DV
Hard to sign participants to separate conditions randomly due to ppts variables which reduces internal validity
Natural experiment
Two levels of IV have occurred naturally without influence of the researcher
Research recorded change in the DV between the two levels of IV
natural experience can happen whenever an event causes people to form into the levels of IV
Strengths of a natural experiment
Allow research in areas that could not happen in controlled experimentation either due to ethical issues or cost
High external validity as natural experiments are in example of real behaviour occurring in the real world free of demand characteristics
Weaknesses of natural experiment
As thesse events would’ve occurred regardless of the researcher they have no influence of controlling extraneous variable so the researcher cannot claim they have found cause and effect relationship
These are very often very rare events that can’t be replicated exactly to test for reliability
Quasi experiments
Participants cannot be randomly assigned between levels of IV
Often because the level of IV is innate characteristic of the participants
Wide range of characteristics that psychologist would like to study, but these characteristics already exist in the sample
For example, age, gender ,income ,education and if you suffer with a mental health condition or not
Strength of a quasi experiment
Only way to experimentally study for factors That are pre-existing characteristics of participants
Weaknesses of a quasi experiment
There may be other factors related to the level of IV that cannot be controlled for
These changes systematically between the levels of IV and alter the measurement of the DV
Known as confounding variables
