Experimental Methods Flashcards
Where are experiments carried out?
In a controlled setting.
What can experiments allow?
They allow us to establish cause and effect relationships because of this control.
What are the 4 types of experiment?
Laboratory, field, quasi and natural experiments.
What is a variable? Give an example.
A variable is something that varies:
E.g. How long you sleep each night is a variable. The number of days in a week isn’t, as it is fixed.
What is the dependent variable?
The variable you measure. Affected by the independent variable.
What is the independent variable?
Directly manipulated by the experimenter.
What does the experimenter decide about the IV and the DV?
The experimenter will decide whether or not the IV caused a change in the DV.
What is operationalisation?
How variables are defined and measured.
Operationalising definitions, means that they have contextualised it to suit their experiment.
How did Schaffer and Emerson operationalise attachment?
Stranger Anxiety.
Separation Protest.
What was the IV and DV in Jacobs’ study? Baddeley? Peterson et al?
Jacobs:
IV: Capacity, digit-span length.
DV: Number of numbers recalled.
Peterson and Peterson:
IV: Duration, trigrams and time-span.
DV: Whether they recall 100% of the trigram.
Baddeley:
IV: Word lists.
DV: Number of substitution errors, how many words were recalled correctly.
Why is control an important aspect in experiments?
Allows the study to conclude cause and effect, meaning you can assume the only variable causing the change in the DV is the IV.
Increases repeatability, this reduces chance and luck.
Reduces extraneous variables.
What is experimental control? Give an example.
All other variables other than IV and DV must be controlled (kept constant.
This is very important, as we are then able to assume that the only variable causing the change in the DV is the IV.
E.g. Baddeley (encoding in STM and LTM) would have had to make sure both words lists had words of the same length, frequency of occurrence in the language etc.
Outline characteristics of a laboratory experiment.
Controlled.
Artificial.
Lacks mundane realism.
Results deemed objective.
Outline 2 strengths of a laboratory experiment.
Can establish cause and effect relationships.
IV = cause, DV = effect.
Replicability (can repeat and achieve same findings).
More objective than other research methods.
Outline 2 weaknesses of a laboratory experiment.
Often lack mundane realism.
Often lack ecological validity.
Often lack experimental realism.
Participants often know they are being observed (respond to demand characteristics).
May cause evaluation apprehension for participants.
Outline two ethical issues that need to be considered when conducting laboratory experiments.
Phobias must be catered for. (E.g. severe phobias can spark anxiety/ depression).
Allergies must be catered for. (E.g. dogs may cause rashes or severe reactions).
Religion must be catered for. (E.g. Muslim women must have the right to keep their hijab on).
Conditions must be catered for. (E.g. flashing lights may cause epilepsy).
Outline characteristics of a field experiment.
Carried out in natural settings such as in the street, in a school, at work etc.
The IV’s are still deliberately manipulated by the researcher.
Participants are not often aware that they are participating in an experiment.
Outline Shotland and Straw’s 1976 field experiment.
A man and a woman (confederates) staged an argument and a fight fairly close to a number of bystanders.
In one condition, the woman screamed, “I don’t know you!”.
In another condition, the woman screamed, “ I don’t know why I ever married you!”.
The experiment found that people were less likely to lend a helping hand when it was a ‘lovers’ quarrel than when it was not.
Outline 2 strengths of a field experiment.
Higher ecological validity than laboratory experiments as behaviour occurs in its own natural environment.
Less bias from sampling (subjects do not have to be bought into the lab).
Lower demand characteristics (if subjects are unaware of being tested).
Outline 2 weaknesses of a field experiment.
Researchers have less control over extraneous/confounding variables, reducing confidence in establishing causal relationships.
It is difficult to replicate the research, making it hard to determine the results’ reliability.
Outline two ethical issues that need to be considered when conducting field experiments.
It’s almost impossible to offer participants the right to withdraw.
You cannot directly ask the participants for consent before it is conducted.
Debriefing should be altered to fit the possible severity of the experiment. (E.g. A small, quick debrief may not be appropriate in catering for the participants if the study was impactful, such as a fight).
When is a quasi experiment used?
When it is impossible or unethical to randomly allocate participants or manipulate the independent variable.
What are quasi experiments? Give an example.
A quasi-experiment is any study where the independent variable cannot be manipulated by the experimenter (e.g. gender, culture, IQ).
For example, to conduct a study on the effects of smoking, you would not be able to randomly allocate people to groups - these groups are pre-existing.
What can the researcher not control in a quasi experiment?
Manipulation of the independent variable is often not under the control of the experimenter.
Not possible to allocate participants randomly to groups in quasi-experiments.
