Location Of the Research

What are the 4 types of experiments?

Laboratory, Field, Quasi, Online

What are the key features of Lab experiments?

1. takes place in a controlled artifical setting (ensures only the Iv is being manipulated)

2. Standardised procedures are used, every participants gets the same experimental experience

3. Experimenter will be manipulating at least one independant variable and measuring at least one dependant variable. (there will be two or more conditions)

4. Often participants know they are in a study- may be deceived about its true aims

5. Usually many participants are tested in a study. The more people you test the more generalisable your results will be

6. Usually 2 or more conditions and experimenter will manipulate variables

Strengths of lab experiments:

• Control over experimental situation- can establish cause and effect relationships

• Extraneous variable can be controlled

• Can be reasonably certain changes made to IV was what caused change in the DV

• Accurate measurements and standardised collection of data- as data tends to be quantitative (no.s) highly objective and less susceptible to subjectivity and interpretation

• Easily replicated as they’re standardised procedures, has high reliability

Limitations of lab experiments

• Low ecological validity- how accurate to real life as they’re standardised procedures often take place under artificial conditions

• As participants may be aware they are in a laboratory experiment- behaviour might change alternatively screw you effect - demand characteristics

• Experimenter effects- experiment displays behaviour influencing participant to act in a certain way

Field experiments

The researcher manipulates at least one IV and measures at least one DV, occurs in a natural environment, often the participant’s own.

Can be conducted out in the street, a school, a hospital or participants own home- setting is sometimes new to participants sometimes familiar

IV is directly manipulated by the researcher no IV not field experiment.

Strengths of field experiments

High ecological value/ validity

no demand characteristics/less

Higher mundane realism (task is like boring real life)

Experiments can still control IV and DV therefore cause and effect relationships can be caused

Limitations of field experiments

Experimenter effects- people reply and act accordingly to how experimenter may reply to them

Demand characteristics still prominent, not fully but people still may be aware they’re in an experiment

Harder to control extraneous and confounding variables- can reduce validity

Risk of demand characteristics Experimenter effects

Ethical issues- no fully informed consent, deception

Harder to replicate- low reliability

Quasi Experiments

There’s an IV, two or more conditions and a DV is measured. The IV isn’t under direct control of the experimenter. IV is a naturally occurring event - researcher can’t directly manipulate. Can be seen as not “true” experiments

Strength of Quasi experiments

Allows research of phenomena that for ethical and practical reasons cannot be studied any other way. Natural experiments enable psychologists to study real problems.

Limitations of quasi experiments

As sub not directly manipulate definite line can’t be drawn of cause and effect conclusions.- change of DV can’t be certain caused by IV

Many extraneous variables can’t be controlled as participants can’t be randomly allocated to experimental conditions

Experiments limited by condition which vary naturally

Replications can be difficult or impossible

Sample of participants may have low generalisability and be a biased sample

Conducting online research

Main type is questionnaires, although it’s becoming more common for researchers to conduct experiments through the internet

Strengths of online research

Large sample of people

Diverse range of participants

Cheaper method of experimentation

Weakness of online research

possible biased sample

Limited research methods offered

Extraneous variables

Confounding variables

Lies and social desirability

Ethical issues

How to reduce demand characteristics?

Single blind procedure- P’s don’t know which condition they’re in so don’t know how they’re supposed to act