Experimental Design Flashcards
what is a laboratory experiment?
experimental methods
an experiment carried out in a controlled environment where the IV is manipulated.
extranoeus variables are controlled
what are 3 key concepts of lab experiments?
experimental methods
- direct manipulation of IV
- contrl
- randomisation
what is direct manipulation of the IV?
experimental methods
when the IV is altered by experimenter to bring about a change
how is control achieved in a lab experiment?
experimental methods
all variables except the IV are held constant and a control group is present to act as baseline
why is control important in a lab experiment?
experimental methods
so that any change observed is known to have been caused by the IV manipulation
how is randomisation achieved in a lab experiment?
experimental methods
ppts randomly allocated to a condition e.g. by flipping a coin or pulling names out a hat
why is randomisation important in a lab experiment?
experimental methods
ensures any extraneous influence from one ppt is as likely to affect one group and it does the other -> little influence on DV
what are strengths of a lab experiment?
experimental methods
- high levels of control
- cause and effect can be established
- high degree of replicability
what are limiations of a lab experiment?
experimental methods
- low ecological validity
- high risk of demand characteristics
- high risk of expeirmenter bias
what is a field experiment?
experimental methods
a controlled study that takes place in a natural setting to measure natural behaviour
what are 2 key concepts of field experiments?
experimental methods
- ppts are often unaware of the study
- IV is manipulated to find a causal relationship
what are strengths of a field experiment?
experimental methods
- cause and effect can be established
- high ecological validity
- low risk of demand characteristics
what are limitations of a field experiment?
experimental methods
- time consuming
- less control of extraneous variables
what is a natural experiment?
experimental methods
a study where naturally ocurring changes to the IV are observed
what are 2 key concepts of natural experiments?
experimental methods
- IV is unplanned and chnages due to naturally occuring events
- no control and no direct manipulation of variables
what are strengths of natural experiments?
experimental methods
- high ecological validity
- useful when unable to manipulate variables
what is a limitation of natural experiments?
experimental methods
difficult to pinpoint cause and effect
what is a quasi experiment?
experimental methods
a study when ppts cannot be randomly assigned to experimental/control groups
what is the point of a quasi experiment?
experimental methods
to create a comparison condition and see how a naturally occuring IV effects different people e.g ages or gender
how are quasi groups brought about?
experimental methods
ppts are matched in some way then put into groups
what is the difference between quasi and natural experiments?
experimental methods
in quasi experiments, its possible to have planned manipualtion whereas in natural it is not.
what is a strength of a quasi experiement?
experimental methods
high ecological validity.
what is a limitation of a quasi experiment?
experimental methods
unable to pinpoint cause and effect
what is an observational technqiue?
observational techniques
making objective systematic observations on behaviours that have been planned in advance.
what is observation useful for?
observational techniques
studying natural behaviours
what are the 6 types of observation?
observational techniques
controlled vs naturalistic
covert vs overt
participant vs non participant
what is a controlled observation?
observational techniques
an observation taking place in a highly controlled environment e.g. a laboratory
what are the strengths of controlled observation?
observational techniques
- high levels of control
- easy to establish cause and effect
what is a limitation of controlled observations?
observational techniques
low ecological validity
what is a naturalistic observation?
observational techniques
an observation of people in their natural environment with no control over variables
what are the strengths and limitations of naturalistic observations?
observational techniques
S: high ecological validity
L: no control of variables
L: cannot establish cause and effect
what is a covert observation?
observational techniques
an observation where ppts are unaware
what are the strengths and limitations of covert observations?
observational techniques
S: natural behaviour observed so increase in validity
L: lack of informed consent = ethical issues
what is an overt observation?
observational techniques
an observation where ppts are aware
what are the strengths and limitations of overt observations?
observational techniques
S: ppts able to give informed consent
L: increased risk of demand characteristics
what is a participant observation?
observational techniques
an observation where the experimenter becomes part of the group being observed
what are strengths and limitations of participant observations?
observational techniques
S: greater insight into behaviour so increase in validity
L: objectivity is affected
what is a non participant observation?
observational techniques
an observation where the experimenter observes from a distance and is not part of the group
what are the strengths and limitations of non participant observation?
observational techniques
S: objectivity increases
L: data lacks richness e.g feelings of ppts
what is self reporting?
self report techniques
when ppts report on themselves
what are the two self report techniques?
self report techniques
questionnaires
interviews
what are the strengths and limitations of self reporting?
self report techniques
S: more detailed access to ppts thoughts and feelings, can investigate what ppt will do in future.
L: rely on honesty, social desirability effects possible
what is a questionnaire?
self report techniques
a list of predetermined questions to which ppts must respond to, in presence or absence of researcher.
what are the strengths and limitations of questionnaires?
self report techniques
S: cheap and time efficient -> easily mass administered.
L: attracts certain type of person (people pleaser) and difficult to phrase in a way that isnt open to interpretation.
what should a researcher consider when designing a questionnaire?
self report techniques
- clarity: is it clear what the Q is asking?
- analysis: is it written so answers be analysed easily?
- sequence: easy to hard Qs will build up confidence in ppts
what are the two type of questions in a questionnaire?
self report techniques
open and closed
what is closed question?
self report techniques
one where ppts can only respond in a certain way by being given a fixed number of responses to choose from (yes, no)
what are the strengths and limitations of closed questions?
self report techniques
S: saves time for both ppt and reseacher, minimum effort required
L: can frustrate ppt when preferred answer isnt offered, large amount of questions = fatigue
what is an open question?
self report techniques
one where the ppts are able to answer freely w/o restriction -> can express opinion and give qualitative data
what are the strengths and limitations of open questions?
self report techniques
S: offers flexibility, can access ppt’s motivations and feelings
L: difficult to analyse, more time consuming for both researcher and ppt
what is an interview?
self report techniques
when ppts answer face to face with researcher.
what are the strengths and limitations of using an interview?
self report techniques
S: well deisgned one can address complex issues, good source of qualitative data
L: answers can be easily influenced by researcher, works bets with confident ppts.
what must a reseracher consider when conducting an interview?
self report techniques
- how will info be recorded?
- has informed consent been given by ppt?
- has a quiet comfortbale location has been chosen?
- are the starting Qs basic neutral ones so more valuable answers are given later when anxiety is lower?
what are the two types of interviews available
self report techniques
structured and unstructured
what is a structured interview?
self report techniques
one that follows a set of predetermined questions.
what are the strengths and limitations of a structured interview?
self report techniques
S: can compare responses to others and identify patterns
L: more time consuming than a questionnaire witth similar structure
what is an unstructured interview?
self report techniques
one which follows a flexible framework and allows interviewer to seek clarification if needed.
what are the strengths and limitations of unstructured interviews?
self report techniques
S: more in depth and detailed answers
L: increased risk of invetsigator bias, information hard to analyse afterwards.
what is a correlation?
correlations
when two or more variables are associated in someway.
what are co-variables?
correlations
the variables measured in correlational analysis
what is correlation?
* a research method
* analysis technique?
correlations
an analysis technique
what do correlations allow researchers to do?
correlations
infer relationships between co-variables
when are correlations useful?
correlations
in situations where it is impossible to do an experimental study e.g. investigating if smoking causes lung cancer.
what are the 4 types of correlational relationship?
correlations
- positive
- negative
- curvilinear
- zero
what is a positive correlation?
correlations
when one variable increases, another increases. e.g temperature and ice cream sales
what is a negative correlation?
correlations
when one variable increases, another decreases e.g. time off work and pay
what is a curvilinear correlation?
correlations
when there is both a positive and negative correlational relationship. e.g. anxiety and achievement
what is a zero correlation?
correlations
when there is a no clear relationship between variables
what are the strengths of correlations?
correlations
- can investigate situtations that can’t be experimentally studied
- indicates both the presence and strength of a relationship
what are the limitations of correlations?
correlations
- the smaller the sample size, the less accurate the coefficient
- cannot reliably establish cause and effect
- only work for linear relationships
how can we indicate the strength and direction of a correlation?
correlations
correlation co-efficient
what is the correlation co-efficient?
correlations
numerical representation of the relationship between co-variables, calculated by Spearman’s Rho
what does the correlation co-efficient range between?
correlations
+1 and -1 (the sign indicating if P or N)
what does +1 mean?
correlations
the perfect positive correlation
how can the correlation co-efficient be used to determine strength?
correlations
the closer the correlation is to +/-1, the stronger the correlation. the correlation grows weaker as it nears 0.
how can the correlation co-efficient be used to determine significance?
correlations
rule of thumb (not always true)
when the co-efficient falls below either +0.5 or -0.5, the relationship is said to be not be significant.
what is the difference between correlations and experiments?
correlations
correlations do not reliably point to cause and effect and do not tell us why there is a relationship. they give us an indication.
what must a researcher decide after correlational analysis?
correlations
how the relationship is interpreted.
what 3 choices does a researcher have when interpreting a relationship?
correlations
- cause and effect explanation
- third variable explanation
- chance explanation
what is the cause and effect explanation?
correlations
the researcher could decide one variable actually caused the other to increase/decrease.
what is the third variable explanation?
correlations
researcher could decide another, in the background variable created the apparent relationship
what is the chance relationship explanation?
correlations
the relationship has no meaning beyond chance - a statistical anomaly
what is content analysis?
content analysis
the analysis of the content of the media
what does content analysis NOT study?
content analysis
behaviour directly
what does content analysis instead investigate?
content analysis
the content of the medium in which behaviour is recorded
what are examples of media analysed in content analysis?
content analysis
- mass media (TV, films, magazines)
- historical documents
what is an example of content analysis?
content analysis
the different ways in which tabloids stereotype genders when discussing men and women
when is content analysis used?
content analysis
when the information needed is too costly or not possible/practical to obtain in other ways
what are the strengths of content analysis?
content analysis
- straight forward to gain access to media that provides rich information
- investigators cannot influence behaviour as no direct contact with people
what are the limitations of content analysis?
content analysis
- may lack objectivity
- description of behaviour, not an explanation.
what is a case study?
case studies
an in depth study of an individual or a group. usually someone whos unique.
how can information be gathered in a case study?
case studies
observation, interview, psychological tests, record analysis
what are the strengths of a case study?
case studies
- large amount of both qualitative and quantitative data can be collected
- detailed insight into the person
- allows research to study things there may not be any way to
what are the limitations of a case study?
case studies
- cannot be replicated
- researcher can become too involved, affecting objectivity
- near impossible to generalise findings
