3) types of experiment

Which variable is manipulated by the researcher?

An independent variable

Which variable is measured by the researcher?

The dependent variable

Which type of experimental method is conducted in a highly controlled environment?

Laboratory experiment

What do laboratory experiment provide?

Laboratory experiments provide:

• high levels of precision

• Use of specialised equipment

why does laboratory experiments have high internal validity?

laboratory experiments have high internal validity because they control extraneous variables, which means that we can ensure that any effects on the DV is likely to be the result of manipulation of the IV

Why is replication more possible in laboratory experiments rather than other experimental methods?

It’s easier to replicate laboratory experiments due to high levels of control

Why is it a benefit that laboratory experiments have high replicability?

laboratory experiments have high replicability because replication is vital to check that the results of a study are reliable and valid and not just a one off

Why do laboratory experiments suffer from lack of generalisability?

laboratory experiments lack generalisability due to the artificial nature of lab experiments (low ecological validity)

Why may laboratory experiments cause demand characteristics?

In laboratory experiments, participants are usually aware they are being tested which can cause unnatural behaviour and decrease the validity of findings

Why do laboratory experiments have low mundane realism?

Laboratory experiments may have low mundane realism because tasks carried out in the lab do not represent real life experience.

What is a field experiment?

A field experiment is an experiment that takes place in a natural, real-world setting, where the researcher manipulates the independent variable and measures the dependent variable but has less control over extraneous variables

Why do field experiments have higher mundane realism than lab experiments?

Because field experiments take place in real-life environments, the situation is more similar to everyday experiences, making the behaviour more natural and realistic.

Why do field experiments have reduced demand characteristics compared to lab experiments?

Because participants are often unaware they are part of an experiment, so they are less likely to change their behaviour based on what they think the researcher expects.

Why is it more difficult to establish a cause and effect relationship between the IV and DV in a field experiment?

it’s harder to establish a cause and effect relationship between the IV and DV in a field experiment due to the lack of control over extraneous variables

Why is replication often not possible for field experiments?

Field experiments take place in natural, real-world settings where variables are not fully controlled. This makes it difficult to recreate the exact same conditions so the study cannot be reliably repeated.

Why may some ethical issues arise in field experiments?

If participants aren’t aware they are being studied during a field experiment, they cannot give consent

What is a natural experiment?

A natural experiment is a study where the independent variable is not manipulated by the researcher but occurs naturally, the variable would have changed even if the experimenter was not interested.

Why do natural experiments have better realism that other experimental methods?

Natural experiments study real-life events, they avoid the artificiality of lab settings which gives it high external validity

Why do natural experiments have reduced demand characteristics?

Natural experiments have reduced demand characteristics because participants aren’t usually unaware of the experiment and the experimenter is usually not present

Why do natural experiments have low replicability?

Natural experiments have low replicability because the independent variable occurs naturally, so the researcher cannot control or recreate the exact same conditions.

Why do natural experiments have low generalisability?

Natural experiments have low generalisability because the events and samples are often unique or specific to a particular context, making it difficult to apply the findings to other situations or populations

Why is the researcher having no control over variables a disadvantage in natural experiments?

Because the researcher cannot control extraneous variables, it is difficult to establish cause and effect. Other factors may influence the results, reducing the validity of the findings.

What is a quasi experiment?

A quasi experiment is a study where the independent variable is based on pre-existing differences between participants (e.g. age or gender), so participants cannot be randomly allocated to conditions.

Why is no random allocation of participants a disadvantage in quasi experiments?

Without random allocation, participant variables (e.g. individual differences) may systematically differ between groups. This introduces bias and makes it difficult to establish cause and effect, reducing internal validity.

Why do quasi experiments tend to have high replicability?

Quasi experiments are often carried out under controlled conditions which allow for replicability to be achieved

Why can we establish a cause and effect relationship between IV and DV in a quasi experiment?

Because in quasi experiments, researchers control extraneous variables, the researcher can be confident in establishing a cause and effects between the IV and DV, which increases the validity of the research.