Correlations, Case Studies and Reviews

• correlations

  • investigate the relationship between between co-variables
  • we show the strength of the association between co-variables by plotting each pair of point on a scatter graph
• positive correlation

  as one variable increases the other increases
• negative correlation

  as one variable increases the other decreases
• zero correlation

  as one variable increases there is no effect on the other
• Correlation coefficients

  used to tell us how strongly the co-variables are related, and this is decided by how close together the points are (a value between 1 and -1)
• evaluation of correlations

  • correlations cannot be interpreted as causation
  • there may be other intervening variables as in a correlational study, there is not manipulation of an IV
  • they are used as a starting point to assess possible patterns between variables before the researchers commit to an experimental study
  • they are quick and economical to carry out as there is no need for a controlled environment and no manipulation of variables is required and secondary data can be used
  • studies only tell us how variables are related but not why and they cannot demonstrate cause and effect between variabkes
  • they can be misused and misinterpreted and third variables can be at work
• meta-analysis reviews

  • primary data results collected indirectly for a specific research purpose, it arrives first hand from the participants
  • secondary data is using the results that were gathered previously by someone else often for a different purpose
  • a process of combining results from a number of studies on a topic to provide an overall conclusion
  • if this is done on quantitative data, the result is called an effect size
  • secondary sources are collected together to investigate a hypothesis
• case studies

  • involve analysis of unusual individuals or events, such as a person with a rare disorder
  • they can also concentrate on more typical cases
  • it involves the production of qualitative data, and the researchers will construct a case history of the individual concerned which may produce more quantitative data
  • they tend to take place over a period of time
  • they can offer rich, detailed insights that may shed light on very unusual and atypical forms of behaviour
  • generalisation of findings in an issue when dealing with small sample sizes
• longitudinal study

  • researchers to not manipulate any variables or interfere with the environment
  • they simply conduct observations on the same group of subjects over a period of time
  • they are beneficial for recognising any changes, developments or patterns in the characteristics of a target population
  • longitudinal studies are often used in clinical and developmental psychology to study shifts in behaviour
• cross sectional designs

  • a type of observational study that involves analysing information about a population at a specific point in time
  • measures the prevalence of an outcome of interest in a defined population that provides a snapshot of the characteristics of the population at a single point in time
  • can be used to assess the prevalence of outcomes and exposures, determine relationships among variables and generate hypotheses about casual connections between factors to be explored in experimental designs