Experimental method Flashcards
What is the difference between an aim and a hypothesis?
Aim= a general statement that describes the purpose of a study
Hypothesis= a prediction of the outcome of a study
What is the difference between a non-directional and a directional hypothesis?
Non-directional= state that an effect will occur
Directional= predict the direction of the effect
When do you write a non-directional and when do you write a directional hypothesis?
Non-directional= there is contradictory evidence and is difficult to predict the direction of the results
Directional= there is evidence to suggest it is likely
What is the difference between the independant and the dependant variable?
Independant= a factor that is manipulated by the researcher
Dependant= the factor you measure and is affected by the IV
What is meant by the ‘operationalisation’ of a variable?
Making the variable measurable
Write an example of a directional and a non-directional hypothesis
Non-directional= there is a difference in reading ability depending on whether people have blue or brown eyes
Directional= people with blue eyes have a better reading ability than people with brown eyes
Describe the 3 experimental designs: independant groups, repeated measures and matched pairs
Independant groups= different participants are used for the 2 conditions of the IV
Repeated measures= the same participants are used for both conditions of the IV
Matched pairs= different participants are used for the 2 conditions, but each group is matched on charcteristics relevant to the study
What are 2 strengths and 2 limitations of independant groups?
Strengths= -no order effects
-demand characteristics less likely
Limitations= -these may affect the DV instead of change in the IV
-more participants needed
What are 2 strengths and 2 limitations of repeated measures?
Strengths= -less participants needed
-no participant variables
Limitations= -order effects
-demand characteristics
What are 2 strengths and 2 limitations of matched pairs?
Strengths= -no order effects
-demand characteristics less likely
Limitations= -Need information to match participants on
-Pre-test may be needed (expensive and time consuming)
Explain how random allocation is used to control for participant variables in an independant groups design
Place letters A and B in a hat and researcher selects them one by one to eachother
OR
Allocate each ppt a number and get a random number generator to select numbers at random, 1st go to condition A and 2nd go to condition B
Explain how counterbalancing is used to control for order effects in a repeated measures design
The participant sample is divided in half, with one half completing the two conditions in one order and the other half completing the conditions in the reverse order
Explain why task difficulty needs to be controlled in a repeated measures design
As it’s the same people doing the experiment, the difficulty must be the same in both conditions so it is the change in conditions alone that caused the change
What is meant by demand characteristics?
Suggest 2 ways these can be controlled
The participant guesses the aim of the study
-Use a double blind design
-Use deception
How can researcher bias affect a study?
Give 2 ways this can be controlled
If a researcher wants a specific answer to the study, they could ask questions differently or use different signals, therefore causing innacurate results
-Use a researcher that doesn’t know the aim of the study
-Use the same criteria for every participant
