week 3 - confounds and controls | Z-scores and testimonials

• When should case studies be used: at the beginning of research to establish a hypothesis, not to test the hypothesis
• What should data collected from a case study aim to do ? Confirm on hypothesis while disproving another, this is why we have control groups and avoids placebo effect
• What is spontaneous remission: When people spontaneously feel better, can relate to mental or physical health
• Describe testimonial vividness: Skews our perception of risk and changes how scientific evidence is evaluated. This can lead to testimonials eclipsing scientific data
• How do we account for the third variable problem: Statistical techniques like partial correlations
• Describe the directional problem: Must recognise that A may cause B or B may cause A
• population varianes

  SS/N
• Sample variance


  SS/(N-1)
• z-scores 


  characterise the position of a data point in relation to the distribution of the rest of the data
• z = 


  (x-mu)/sd
• within 1 and 2 sd

  68.3% and 95.4%
• case studies


  studying one person or group in detail, collecting rich qualitative data
• testimonials 


  individuals confirming that a treatment works
• third-variable problem


  another variable may be responsible for the changes in the IV and DV which was not measured
• selection bias


  people have an influence over their environment to a degree therefore situational and environmental factors influence each other
• placebo effect


  patients convincing themselves that a treatment works because they believe it will
• P.T. Barnum effect


  people will believe generalised personality descriptions relate to them