Research Methods-Experiments Flashcards
Define Laboratory Experiment
Experiments in a lab where variables can be controlled.
List advantages of laboratory experiments
Easily controlled.
High in validity.
Reliable as they can be easily replicated
List disadvantages of laboratory experiments
Low in ecological validity (doesn’t replicate real life).
Demand Characteristics mean they could work out the study and behave how you want them to.
Define Field Experiment
Experiments done in natural environment e.g. classroom
List advantages of field experiments
High in ecological validity.
Natural environment comparable to real life.
No demand characteristics if participants unaware increasing the validity.
List disadvantages of field experiments
Researcher cannot control all factors e.g. time and weather.
Raises ethical issues if participants are unaware.
Define Naturalistic (Quasi) Experiments
Can be a natural lab experiment or natural field experiment.
List advantages of naturalistic experiments
Allows us to access groups that would otherwise be unethical or impossible to test.
List disadvantages of naturalistic experiments
Can be difficult to get participants.
Define independent variable
The variable that the researcher manipulates.
Define dependent variable
A particular behaviour that is dependent on the way the experimenter manipulates the independent variable.
Define experimental (alternate) hypothesis
Tests the cause of independent variable on the effect of dependent variable
Define directional hypothesis (1 tailed hypothesis)
Predicts the direction in which results are expected to occur.
Define non-directional hypothesis (2 tailed hypothesis)
Does not predict the expected direction of outcome but will state that there is some kind of difference between the two events
Define null hypothesis
Predicts that there will be no differences between the two variables
Define extraneous variables
Things that affect the behaviour of participants e.g. environmental conditions like light, noise and heat.
Define confounding variables
When the extraneous variables align themselves with the experimenter’s manipulation of the independent variable. It confounds the experimenters attempts to interpret the findings of the experiment in the intended way.
Define independent measures
Involves using different participants in each of the experimental designs. By comparing the performance of participants between conditions, you can establish whether or not the independent variable affects the participants’ behaviour.
List advantages of independent measures design
No problems caused by order affects (where learning, boredom or fatigue can influence the second condition).
List disadvantages of independent measure design
Differences in performance between two groups may be due to individual differences rather than manipulation of independent variable.
Define repeated measures
Comparing the performance of people in one condition with their own performance in another condition.
List advantages of repeated measures design
Individual differences are removed.
List disadvantages of repeated measures design
There are order effects.
Participants may perform better in the second condition because of the practice they will have gained during the previous condition (positive order effect). They may perform worse as a result of boredom (negative order effects).
Define matched pairs
Matching participants in one of the conditions to another one of the participants in the second condition according to variables that are considered to be relevant to experimental conditions. E.g. may be matched for age, gender and intelligence.
