Aims and Hypothesis

• Most aims begin with "to investigate"
• An experimental/ alternative hypothesis predicts how the change in an IV's conditions will significantly effect the DV
• An example of an experimental/ alternative hypothesis:

  Participants given a spider to hold (IV) will have significantly different heart rates (DV) than those given a puppy to hold (IV)
• A correlational hypothesis predicts a relationship between 2 co-variables
• An example of a correlational hypothesis:

  There will be a significant relationship between the number of spiders (Co-variable 1) in a given area and the weight of frogs (Co-variable 2)
• If in a hypothesis there is no mention of relation or correlation then the hypothesis is experimental
• What are the 2 main ways of writing a hypothesis?

  Non Directional and Directional
• Experimental method involves the manipulation of an Independent variable to measure the effect on a dependent variable
• Define aim

  A general statement of what the researcher intends to investigate, the purpose of a study
• Define hypothesis?

  A clear statement that states the relationship between the variables to be investigated
• What is a directional hypothesis?

  A hypothesis that states the direction of the difference or relationship between 2 variables. "therapy decreases depression" is a directional hypothesis as it predicts a specific event
• What is a non-directional hypothesis?

  A hypothesis that doesn't state the direction of the difference or relationship. "Therapy has an effect on depression" Doesn't say whether there is an increase or decrease
• What is an IV?

  An independent variable that is some aspect of the experimental situation that is manipulated by the researcher or changes naturally, so the effect of the DV can be measured
• What is a DV?

  Dependent variable that is measured by the researcher, any effect on the DV should be caused by a change in the IV
• Define operationalisation

  Clearly defining variables in terms of how they are measured
• A null hypothesis is the prediction that no significant difference/correlation will be found and that the findings are just due to chance
• The null hypothesis is always non-directional
• Non directional hypothesis are 2 tailed
• Directional hypothesis are one tailed
• Correlational null hypothesis example:

  There will be no significant relationship between Co-variable 1 and Co-variable 2 and any relationship found will be down to chance
• You can operationalise (add more detail to an IV and a DV) in a hypothesis