Research project

Research project

1. Null Hypothesis

   • No relationship of variables or correlation
   • IV does not affect the DV

2. Alternative Hypothesis

   • There is a relationship between variables
   • IV affects DV
   • One-tailed hypothesis
     • Predicts what direction the results will go
     • Clear prediction of how the IV will affect the DV
       • Usually from previous evidence
   • Two-tailed hypothesis
     • Can predict that the IV will affect the DV
       • No explanation

3. If the null hypothesis is rejected because there is a difference an alternative hypothesis is accepted

4. Operationalism

   • Variables
     • Operationalising defines variables
       • To manipulate the IV
       • To measure the DV
     • If the IV and DV are operationalised...
       • The research can be replicable
     • Control of variables
       • Variables that are difficult to control
         • Change between conditions
         • e.g. How tired the participants are
         • Other variables, apart from the IV, may affect the DV
       • How?
         • Using standardised procedures
         • Carry out a pilot study
           • Trial study
           • Advantages
             • Can make improvements
             • Not waste resources
   • Example
     • Memory
       • Operationalised: the number of words remembered from a list of 20 words

5. Reliability

   • Consistency
     • Multiple measurements should have the same effect
   • Internal Reliability
     • Consistency within the study
     • To test internal reliability...
       • Split-half technique
         • Half of the scores compared with the other half for similarities
   • External Reliability
     • Consistency of repetition in a study
       • e.g. Personality of a participant tested on more than once
     • To test external reliability...
       • Test-retest method
         • Participants tested on more than once to test whether the results stay similar
   • Inter-rater Reliability
     • Similarities of several observers' results
     • To improve reliability...
       • All observers' must have operationalised categories of behaviour and must be trained probably
     • Measured by...
       • Correlational analysis
         • High positive correlation = high inter-rater reliability

6. Validity

   • Whether a measurement technique measures what it is supposed to
   • Internal Validity
     • Did the IV cause the affect on the DV?
     • A lack of validity is caused by...
       • Demand characteristics
       • Uncontrolled variables
     • Mundane Realism
       • Do the measures used generalise to real life?
         • e.g. Does the measure of long-term memory on remembering a list generalise to how people remember past events?
         • Contributes to ecological validity
   • Ecological Validity