types of hypothesis

• experimental/alternative


  predicts that the IV will have an affect on the DV.
• null 


  predicts that the IV will have no significant effect on the DV, or any difference between the two conditions will be due to chance factos.
• directional hypothesis


  predicts that the IV will have an effect on the DV and states exactly how this difference will occur.

  • this is used when previous research is fairly conclusive and the researcher is confident about what they expect to find.
• non-directional hypothesis 


  predicts that the IV will have an affect on the DV but doesn't predict exactly how.

  • used when there is limited previous research and the researcher is unsure about what they may find.