Variables Flashcards
define variables
Any ‘thing’ that can vary or chnage within an investigation. Variables are generally used in experiments to determine if changes in one thing result in changes to another.
define IV
Independant variable:
Some aspect of the experimental situation that is manipulated by the researcher - or changes naturally - the effect on the DV can be measured.
define DV
Dependant variable:
The varibale that is measured by the researcher. Any effect on the DV should be caused by the change in the IV.
define operationalisation
Clearly defining variable in terms of how they can be measured.
Operationalise the hypothesis:
‘The group that drinks an energy drink will be chattier than the group that drinks water’
Afer drinking 300ml of [insert name of energy drink] participants will say more words in the next 5 minutes than participants who drink 300ml of water.
What are the names of other variables that can affect the results of an experiment
Extraneous variables
define extraneous variable
EV: Any variable, other than the IV thant may have an effect on the dependent variable if it is not controlled. They do not vary systematically with the IV
EVs are essentially nuisance variable that do not vary systematically with the IV
Define confounding variables
Any variable, other than IV that may have affected the DV so we cannot be sure of the true source of changes to the DV. They vary systematically with the IV
What is the difference between EVs and confounding variables
confounding variables vary systematically with the IV whereas EVs don’t
How many types of extraneous variables are there
4
What are the types of extraneous variables
- Situational variables
- participant variables
- experimenter/ investigator effects
- demand characteristics
Define situational variables
aspects of the environment that might affect the participant’s behaviour
e.g. lighting, temperature, noise
They should be controlled so they are the same for all participants
How do you deal with situational variables
Standardised procedures are used to ensure that the conditions are the same for all participants. This includes the use of standardised instructions.
Define participant (/person) variables
This refers to the ways in which each participant varies from the other, and how this could affect the results.
e.g. mood, intelligence, anxiety, concentration etc.
How do you control participant variables
participant variables: controlled using random allocation to the conditions of the independant variable
What type of variables does order effects belong to
situational
How do you control order effects
order effects: controlled using counterbalancing
define counterbalancing
An attempt to control for the effects of order in a repeated measures design: half of the participants experience the conditions in one order and the other half in the opposite order
How does counterbalancing act as a control
It prevents improvement in performance due to practice or poorer performance due to boredom.
define investigator/ experimenter bias
Where the experimenter unconsciously conveys to participants how they should behave.
how can the investigator effect the behaviour of the participants
- by giving unintentional clues to the participants about what the experiment is and how they want them to behave.
- their personal attributes e.g. age, gender, accent, manner etc. can affect the behaviour
Define demand characteristics
Any cue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose of the investigation.
What are the aspects of demand characteristics
- the surroundings
- the researcher’s characteristics
- the researcher’s behaviour
- their interpretation of what is going on in the situation.
How are demand characteristics reduced
minimise the factors by keeping the environmnet as natural as possible and by following standard procedure.
