Research methods: Types of experiment Flashcards
What are the 4 main types of experiment?
Lab, Field, Natural, and Quasi
Define a lab experiment
The high level of control the researcher has over all the variables in the study
What environmental factors will the researcher control in their lab experiment. How do they do this?
e.g. the noise, the temperature and the experience each participant has/ the instructions they are given. They do his through standardised procedures.
In a lab experiment, how many variables change? What is the name of the variable? How does this variable change? Why do they want this variable to change?
Only one variable changes. This is called the independant variable. The researcher manipulates this independant variable. By changing the IV, the researcher can mesure the effect on the DV
Exluding the IV and DV, what happens to the other variables during a lab experiment?
They are kept constant/ do not change
Name and describe one strength of lab experiments.
Researchers are confident in establishing a cause and effect relationship: This is due to the high level of control lab experiments allow for e.g. exluding the IV and DV, all other variables are held constant.
Name a second strangth of lab experiments
They have high internal validity: Meaning the observed change in the DV is due to changes in the IV
Name a third strength of Lab experiments
They are easily replicable: This is due to the use of standardised procedures
Name and describe a weakness of a lab experiment
They lack ecological validity (which is a type of external validity): This makes it harder to generalise findings from lab studies to real world situations
Name and describe a second weakness of lab experiments
They lack mundane realism: This is because they don’t reflect the kind of tasks performed in real world situatioons (therefore leading to lowered external validity).
Name and describe a third weakness of lab experiments
Participants know they are being studied: They may alter their behaviour due to demand characteristics (changing behaviour to match the aim of the experiment/ what the researcher wants).
Define field experiment
Conducting the experiment in a naturalistic setting
By doing a field experiment, the researcher avoids what?
It is done as an attmept to avoid the artificial nature of lab studies
What are some common examples of locations used in field experiments?
Shopping centers, places of work, and chools
What is a similarity between a field and a lab experiment?
The independant variable is still manipulated by the researcher between conditions and the change in DV is measured
Name and describe one strength of a field experiment. What is it high in?
More natural behaviour: This is due to the participants being in a natural/ normal environment. This makes it so the behaviours observed can be applied to other naturalistic settings (making them high in ecological validity)
Name and describe a second strength of field experiments
Tasks have high mundane realism: The task may closer resemble tasks the participant would usually participate in in their daily life.
Name and describe a third strength of field experiments
No demand characteristics: This is due to the participants not knowing they are being studied, therefore making them act naturally.
Name and describe one weakness of field experiments
Lack of control over extraneous variables: This could influene the measurement of the DV
Name and describe a second weakness of a field experiment
It is difficult and in some cases impossible to assign participants to random conditions: This shows how changes in the DV may be due to participant variables (therefore reducing internal validity).
What’s different about a natural experiment compared to for example a lab or a field experiment?
In a natural experiment, the levels of independant variable have already happened naturally.
Define a natural experiment
The two levels of independant variable have (or will) occured naturally (in the real world)without the influence of the researcher. The researcher simply records the change in the dependant variable between the two levels of the IV.
Name and describe one strength of a natural experiment
Natural experiments allow research in areas that could not happen in controlled experimentation, either due to ethical or cost reasons.
Name a second strength of Natural experiment
They are high in external validity: This is due to them being done in the real world stopping any form of demand characteristics
Name one weakness of natural experiments
Can’t establish cause and effect: This is due to lack of control over extraneous variables. These events will hppen/ have already happened, regardless of th researcher
Name a second weakness of natural experiments
Can’t replicate them: the events are often rare. This therefore lowers reliability.
Define quasi experiment
Participants cannot be randomly assigned between levels of IV. Often becuase the level of IV is an innate characteristic of the participant.
Name examples of things that you could identify a quasi experiment with
Age, gender, do or do not have a mental disorder. Thes are innate an cannot be changed
Name and describe one strength of a quasi experiment
They are the only way to study factors that are pre-existing characteristics of participants.
Name and describe one weakness of quasi experiments
There may be other factors related to the level of IV that cannot be controlled for, these change systematically between the levels of IV and alter the measurement of the dependant variable. These area known as confounding variables
