Experimental Method Flashcards
What do psychologists do
They come up with a theory and prediction then experiment it and create an observation
what is a hypothesis?
Directional hypothesis?
Non directional hypothesis?
null hypothesis? +
hypothesis = A precise testable statement about the assumed relationship between variables (predictions)
Directional hypothesis = (Already has some evidence) A change in the direction and the change is stated e.g. Girls will get better grades than boys
non-directional hypothesis = ( No evidence ) where it predicts the change but not the direction e.g. there will be a difference in gcse result’s between boys and girls
null hypothesis = states no significant difference exists e.g. There will be
no relationship between boys and girls gcse results
what is the independent/ dependant variable and operationalisation
independent = thing you change
dependent = Thing you measure
operationalisation = clearly defining the variables in terms of how they can be measured
Are these examples directional or non-directional?
“lack of sleep affects reaction time “
“ girls talk more than boys “
“the faster you drive the more likely you are to crash”
“ the quality of service in a restaurant affects its popularity”
non-directional
directional
directional
non-directional
what are extraneous variables
any variable other than the iv that affects the dv if not controlled.
what are extraneous variables divided into and there definitions
demand characteristics = any clue from the researcher that the participants may interpret to reveal the purpose of the investigation (participants may change there behaviour )
investigator effects= Any effect of the researchers behaviour on the out come of the research e.g. bias
participant variables = individual difference’s such as IQ, sleep, gender, age
situational variables = environmental differences such as noise, lighting , instructions, how close the screen is
how can psychologists control extraneous variables in an experiment?
standardisation = using the exact same instructions for all participants ( high control )
randomisation = use of chance to control the effects of bias when designing materials and order of conditions.
what is the study of control vs realism
and mundane realism
if the set up of a study is too artificial then the participant’s will not act as they would normally. Mundane realism refers to how an experiment mirrors in the real world meaning if something is lacking mundane it means its not like real life so cant be used.
Write a hypothesis
participants were told they would be placed in a booth and would have to read out an article to an audience but they cannot see them but only hear them and cannot interact with them
condition A - 10 participants were told they have an audiance of 5 listeners
condition B - the other 10 were told they had a audience of 100
each participant completed the study individually. The psychologist recorded the presentations and counted the number of verbal errors made by each participant
” There will be a difference in the number of verbal errors made by people reading to 5 people compared to people reading to 100 people”
what is the repeated measure design
There is only one group of participants. This group takes part in both conditions ( experiences both levels of the iv )
What are the positives and limitations of the repeated measures design
positives = participant variables are eliminated
limitations = may be more confident the 2nd time around
may have situational factors as an issue
may get bored
( ORDER EFFECTS e.g. practise, fatigue )
what is experimental design
How participants are allocated to the different conditions in an experiment
How to deal with the limitations in the repeated measures design
Half of the participants do A first then B. Then the other half do B then A
( counterbalancing )
what is the independent groups design?
There are 2 separate groups of participants. One takes part in condition A and the other in condition B
what are the limitations of the independent groups design and how to deal with the limitations
personality can effect because there will be participant variables
Random allocation can be used using a random number generator to select the participants into groups
What is the matched pairs design
There are two separate groups but they are split into pairs for certain qualities such as age or intelligence. One of each pair does condition A and the other condition B
What are the limitations of the matched pairs design and how can we deal with them ?
participant variables will still be present because they cannot be fully matched up
confidence
time consuming and expensive
piolet study = Doing a trial run of the research designed to pre-match the participants
what is Order effects and what design do we see it in
Order effects = An extraneous variable from the order in which the conditions are presented e.g. practise, fatigue , boredom , demand characteristics
repeated measures
What is counterbalancing and what design do we see it in ?
Half of the participants do A and then B and the others do B then A (ABBA)
Repeated measures
what is random allocation and what design do you see it in?
Ensures each participant has the same chance of being put into either condition
reduces bias
independent groups
what is the pilot study and what design would you find it in?
The run of a research methods to pre match participants on the main variables
matched pairs
What is reliability and validity
reliability = How consistent the findings are (consistency) - replicate it, standardisation
validity = does the study measure what it is suppose to measure?
What is Internal validity and External validity
internal validity = Control of EVs
External validity = can you generate the results to the real world
what are the different types of experiments
- Laboratory experiment
- Feil experiment
- Natural experiment
- quasi experiment
What is the laboratory experiment
and the strengths and weaknesses
controlled artificial environment ( lab )
strengths = Ev’s are controlled.
researcher is detached
High internal validity
standardised
weaknesses = lacks external validity
demand characteristics They know they are being researched (can compromise validity)
What is field experiments
and what are the strengths and weaknesses
example
An experiment in an everyday real life setting
strengths = behaviour is realistic
higher external validity
less chance of demand characteristics
weaknesses = ev’s are difficult to control
ethical issues-people haven’t consented
low in internal validity
Bickman
what is a natural experiment and its strengths and weaknesses
researcher hasn’t changed the iv (already happened in society)
used when its not practical/ethical to manipulate the iv
strength = natural - iv has naturally happened
can be useful when not practical or ethical
weaknesses = difficult to control
children who have been adopted and fostered
experience of robbery
What is a quasi experiment
existing differences in people you cant manipulate e.g. gender
having existing mental illnesses
What is random sampling and what are the strengths and weaknesses
- All members of the population have an equal chance of being selected e.g. lottery method
strengths - prevents researcher bias - large samples can be representative
weaknesses - Time consuming - may not be representative
- Difficult
What is a systematic and stratified sample and what are the strengths and weaknesses
systematic - Every nth participant is selected
same interval e.g. every 3rd person
strengths - Avoids researcher bias
- usually fairly representative
weaknesses - May be biased using a system to select participants e.g. if it was every 10 but the list was boy ,girl, boy ,girl
stratified Dividing the target population into sub categories then choosing a sample from each category e.g. if 60% of the people were girls and 40% were boys and you need 10 people you would take 6 girls and 4 boys.
strengths- representative
generalization is possible
weaknesses - time consuming
- complete representation cannot be met
What is opportunity and volunteer sampling and what are the strengths and weaknesses
opportunity - selecting anyone who is willing and available at the time
strengths - quick and convenient, economical ( most practiced sample )
weaknesses - bias because you will get a certain type of person
- unrepresentative
- researcher bias
volunteer - when people actively volunteer by responding to and advert etc.
strengths - minimal input from the researcher, convenient, quick
weaknesses - bias may get one type of person e.g. people who are helpful and confident
- unrepresentative
What does
- population
- sample
- bias
and generalizability mean
- population = A group of people that the researcher is interested in / focus of the investigation
- sample - A group taken from the population /group of people in the research that is representative to that population
- Bias = where one group is over or under represented
- generalizability = extent to which findings and conclusions can be applied to the population
What does
- Ethical issues and the BPS mean
Ethical issues - When a conflict arises between the rights of the participants and the research
Bps - Is the British psychological society which instructs psychologists how to carry out their research and what behavior is and is not acceptable
What is deception and the right to with draw and how to you deal with these ethical issues
deception - Deliberately withholding information in any stage of the investigation to the participant.
- If the participant is deceived you must make sure that there is a debrief after the investigation where nothing is withheld
- give the right to withdraw once told about the investigation
Right to withdraw - make sure every participant can withdraw at any stage and how to withdraw and to make sure they don’t feel obliged to continue
- they can sign a form
- the have the right to withhold data
What is informed consent and protection from harm and how can these ethical issues be dealt with
informed consent - participants should know as much as possible before the research before they agree to take part but this can cause demand characteristics ( bias )
- sign a form
- Have a debrief after the investigation so they can have the right to withdraw information
protection from harm - Participants should not be placed in anymore harm than they would in their daily lives and participants should leave in the same state they entered
e.g. not overloading them with coffee
- full debrief
- counselling if psychologically harmed
- right to withdraw
What is privacy and confidentiality and how to deal with this ethical issues
Participants have the right to control their personal information and not data should be leaked ( more likely in field experiments )
- simply don’t record any personal information refer to the participants as numbers
- blur faces
- debrief and right to withdraw
What are pilot studies
Small scale - trial run of the actual investigation to check procedures (If it works) standardized instructions
it ensures high validity and reliability
What are examples of a pilot study
- pre match participant variables in a matched pairs design
- lab experiments : checking if a situational variables are controlled and there’s a standardized procedure
- questionnaire : Check if the questions make sense/ have clarity
- train researchers
What can you use to control and experiment
and what are they and what do they eliminate?
what type of experiments would you find them in
single blind - Where the participants are unaware of the aim of the study and unaware of what condition they are in. The researcher is aware of the test .This eliminates demand characteristics
Double blind - This is where the researcher (who comes face to face) and the participant don’t know the aims of the experiment or what conditions they are in. This helps to eliminate demand characteristics and researcher bias
Control group - A neutral comparison group to compare the iv conditions with them
Drug experiments
what is peer review
how is psychological research published
The assessment of scientific work by other psychologists who are experts in the same field, to ensure that any research intended for publication is of high quality
journal article
What is the purpose / aims of peer review
- The research is reviewed by the peers (other psychologists in the same field)
- The report is considered in terms of its validity, significance and originality
