Experiments (Method + Design) Flashcards
what is the experimental method?
an experiment sets out to test a research aim and hypothesis.
What is a true experiment?
a study of difference and is nomothetic. differs from non-experimental methods, involves deliberate manipulation of one variable while trying to keep all other variables constant.
What is the IV?
Independent Variable- research manipulates
What is the DV?
Dependent Variable- variable that is measured
Characteristics of a true experiment
- Researchers are looking for a different between conditions
- Researcher look to manipulate the operationalised IV
- Control (Extraneous Variables) and measure/record a change in the operationalised DV
- Researchers will randomly allocate participants to each condition
Types of experiments
-Laboratory Experiment
-Field Experiment
-Quasi Experiment
-Natural Experiment
Experimental Designs include:
repeated measures, independent group, matched pairs
What is the independent group design?
Different participants are placed in each condition. it is used to ensure that results are not influenced by order effects, to reduce the chance of demand characteristics and when repeated measured designs cannot be used
Strengths of Independent group design:
-researchers only need to produce one set of stimulus materials
-order effects are reduced bc participants only experience one condition, increases validity
-reduces chance of demand characteristics
Limitations of Independent group design:
-individual differences may confound the results
-more participants are required than in other designs, makes design expensive to use large sample size
What happens in Repeated Measures Design?
Same participants are used in both conditions.
Used to reduce the influence of individual differences and where participants are difficult to sample
Strengths of repeated measures design:
-individual results do not affect the results or any subsequent conclusions
-design is efficient; only one set of participant expenses
Limitations of repeated measures design:
-participants experience both conditions so demand characteristics might confound the results
-at least 2 sets of stimulus materials are required
-increased chance of demand characteristics
What happens in Matched pairs design?
different participants are used in each condition but they are matched on key variables to form pairs
Strengths of matched pairs:
-researchers only need to produce one set of stimulus materials, reduces chances of confounding variables associated with the materials
-order effects are reduced bc participants only experience one condition- validity