Experimental Research Method Flashcards
What are the four types of experimental methods used to carry out research?
- Laboratory experiment
- Field experiment
- Natural experiment
- Quasi experiment
What is a research method?
It is a particular way of studying something in order to discover new information about it or understand it better
Definition of a laboratory experiment
- A controlled environment where extraneous and confounding variables are regulated
- Artificial environment
- Participants go-to researcher
- IV manipulated
Advantages of laboratory experiment
- EVS and CVs can be controlled - the effect of EVs and CVs on DVs can be minimized.
- Cause and effect between IV and DV can be demonstrated (high internal validity)
- Can be easily replicated
- Due to standardised procedure the experiment can be repeated
Disadvantages of a laboratory experiment
- May lack generalisability
- Controlled lab environment may rather be artificial and participants are aware they are being studied
- Behavior may not be ‘natural’ and can’t be generalized to everyday life (low external validity)
- Demand characterostocs
- Cues in an experimental situation that invite a particular response from participants. Results of the experiment may be explained by the cues rather than the effect of IV
What is field experiment?
- Natural setting - real life
- Researcher goes to particpant
- IV is manipulated and effect of DV is recorded
Advantages of field experiment?
- More natural envnirnoment
- Particpants are more comfortable in own envirnoment so results may be more generalisable to everydaylife
- Particpants may be unaware they are studied
- They are more likely to behave as they normally do so findings can be generalised. Study has greater external validity
Disadvantages of a field experiment
- More difficult to control CVs as observed changes in DV may no be due to IV to Cv
- Difficult to establish cause and effect than in the lab
- There are ethical issues
- Participants in field experiment may not give informed consent, this is an invasion of participant’s privacy which raises ethical issues
What is natural experiment?
- Experimentor does not manipulate the IV
- IV would have been more varied if experimentor wasn’t interested
- DV may be naturally occuring (e.g exam results ) or may be measured by experimentor
Advantages of natural experiment
- May be the only ethical option
- Unethical to manipulate the IV e.g studying the effects of insititutionalisation of children. Only way casual research done for such topics
- Greater external validity
- Natural experiments involve real-life issues such as effects of natural disaster and stress level
- Findings are relevant to real-life
- Natural experiments involve real-life issues such as effects of natural disaster and stress level
Disadvantages of natural experiment
- Natural event may occur rarely
- One off event reduces opportunity for research . This may limit scope to generalise findings to other similar situations
- Particpants are not randomly allocated. The experimenter has no control where particpants placed as IV pre-exisitng. Result in CV not controlled
What is quasi-experiment?
IV is based on pre-exisitng difference between people e.g age or gender
No one has manipulated variable it simply exist
DV may natural occur (Exam results) or may be measured by the experimentor
Advantages of quasi-experiment
- High control
- Carried under controlled conditions and therefore shares some strengths of lab experiments so increased confidence to draw conclusions
- Comparisons can be made between people
- Quasi-experiment, IV is difference between people. This means that comparisons between different types of people can be made
Disadvantages of quasi experiments
- Particpants are not randomly allocated
- Experimentor has no control over particpants as IV is pre-existing.Particpant variables may caused the change in Dv acting as CV
- Casual relationships are not demonstrated
- Researcher does not manipulate/control the IV and cannot say certain chain in DV due to IV
Research issues
Investigator effect
This can occur when the researcher unintentionally/unconsciously influences the outcome of the research they are conducting
e.g Age
Gender - gender bias
Non-verbal
Physical
What is demand of characteristics?
Refers to any cue from researcher or research situation that may reveal the aim of the study - influence particpant’s behaviour
e.g experimentor body language
unconsciously influence particpant’s behaviour
Screw you effect - screw up data
What is ecological validity?
Degree om which materials and procedures involved in experiment similar to events that occur to other social settings and help to generalise tot hem
e.g Milgram
What is mundane realism?
Degree to which investigation represents other social settings
Identify research method:
Two primary schools use different reading schemes. A psychologicist compares the reading scores at the end of the year to see which one is effective
Natural experiment - used everyday life
Identifiy research method
Children go to local church hall to take part in a trial to compare success of a new maths programme. Children are placed in one of two groups - a group recieveing the new maths programme or recieveing traditional one
- Lab experiment
Identify research method
Rates of diagnosis for depression were comapred before and after September 11th terrorist attack
Natural experiment
differences already established
Identify research method
Men and women were tested on how willing they are to obey orders in Milgram-type experiment
Quasi - men and women
Identify research method
People were observed on a train to see if they were more likely or less likely to help someone appeared drunk ,homeless , male or female
Field experiment
What is an example of a labortory experiment?
Milgram’s experiment on obedience or Loftus and Palmer’s car crash study.
What is an example of a field experiment?
Holfing’s hospital study on obedience.
Hofling (1966) created a more realistic study of obedience than Milgram’s by carrying out field studies on nurses who were unaware that they were involved in an experiment.
What is an natural experiment?
Hodges and Tizard’s attachment research (1989) compared the long term development of children who have been adopted, fostered or returned to their mothers with a control group of children who had spent all their lives in their biological families.
What is the difference between mundane realism and ecological validity?
- Mundane realism-can the results of a study be applied to everyday life? E.g. How often would we be asked to give electric shocks as a punishment for giving wrong answers in real-life (as the participants did in Milgram’s (1963) obedience to authority study)?
- Ecological validity-can the results of a study be applied to different environments/settings? E.g. Milgram replicated his study in different environments (e.g. rundown office block) with different procedures (forcing learners hand onto a ‘shockplate’, giving orders via telephone etc). Thus, it could be argued that his research has ecological validity as it took place in the different environments and settings previously described. NB. It’s possible for a study to lack both ecological validity and mundane realism or lack one but not the other.
