Research Methods:Types of experiment , experimental design and terminology Flashcards
What is an aim?
a statement or question about what you are intending to research
What is a hypothesis?
a precise , testable statement of what the researcher predicts will be the outcome of an experiment
What is a null hypothesis?
What is an experimental hypothesis?
-a statement of no difference (the IV wont impact the DV)
-statement of how the IV will effect the DV
What is an independent variable?
the variable that is manipulated by the researcher
What is the dependent variable?
the variable that the researcher measures
What is a directional hypothesis?
What is a non-directional hypothesis?
states the kind of difference you are expecting between the groups/conditions
states their will be a difference but unknown as to which way
What does operationalisation mean?
turning abstract conceptual ideas into measurable and testable observations
What is an extraneous variable?
any variable apart from the IV that may affect the DV
What is a cofounding variable?
a type of EV that is related to the IV so can act as another IV
What are demand characteristics?
cues that may indicate the aim of a study to ppts
What does standardisation mean?
process of procedures used in research being kept the same
What is counter-balancing?
where one group does the conditions in one order and the other does them in the opposite order
-ensures each condition is tested equally
What are order effects?
when ppts responses are affected by the order of conditions to which they were exposed
What is a lab experiment?
What are the strengths(2)and weaknesses(2)?
conducted in a controlled environment
the IV is manipulated by researcher
+precise control of variables so can be confident that the IV has caused the change in DV
+easier to replicate which allows us to check reliability
-high control can make it artificial which make its difficult to generalise findings so can lack ecological validity
-may behave differently in a lab to real life
What do standardised instructions allow?
allow experiments to be done by anyone at any time
What is a field experiment?
What are the strengths(2) and weaknesses(2)
carried out in a real life setting , but the researcher still manipulates the IV
+higher ecological validity as done in a natural setting so findings can be generalised more easily
+ppts less likely to show demand characteristics as they behave more naturally as they aren’t aware they are being studied
-less control over EVs which lowers validity as cant establish cause and effect
-ethical issues as ppts often aren’t aware they are taking part
What is a natural experiment?
What are the strengths(2) and weaknesses(3)
done in a natural environment , researcher does not manipulate the IV
+high ecological validity
+useful to look at situations where IV manipulation would be unethical
-loads of EVs that cant be controlled (cant est cause and effect)
-not easy to replicate
-risk of cofounding variables due to no random allocation
Name the three experimental designs
independent groups
repeated measures
matched pairs
What is an experimental design
how ppts are allocated to different conditions of an experiment
Describe an independent groups design
2 points
-each ppt takes part in 1 condition
-they are randomly allocated to their condition
What are the 2 strengths of an IG design and what are the 3 weaknesses?
+no order effects
+reduced chance of demand characteristics
-no control over ppt variables
-differences between conditions many be due to use of different people instead of the IV
-need twice as many ppts
Describe a repeated measures design
2 points
-same ppt is used in both conditions
-same person does each task and is tested several times
What are the 2 strengths and 2 weaknesses of a RM design?
+ppt variables are eliminated
-less time consuming as you need less ppts
-order effects may alter performance
-increased chance of demand characteristics
Describe a matched pairs design
2 points
-ppts matched as closely as possible with another using a pre-test
-each member of the pair is randomly allocated to one of the conditions
What are the 2 strengths and 2 weaknesses of a MP design?
+no order effects
+control of ppt variables
-time consuming as have to match ppts
-requires more ppts
How do you control the issues with each of the experimental designs?
IG-random allocation to conditions
RM-counterbalancing conditions controls order effects
MP-random allocation
What does random allocation do?
chooses individuals entirely by chance with no regard to will of researchers/ppts preference or condition
