Correlations

• Tips


  -don't use the following terms: 'effects', 'difference', 'compared to'

  -only collect quantitative data

  -measuring co-variables (there is no IV/DV)
• What are correlations


  -a statistical technique

  -involves measuring + looking for a relationship between 2 variables (co-variables)

  -cause and effect cannot be established
• What is a positive correlation


  relationship between variables where as one increases, the other increases e.g as temp increases, the number of ice creams sold increases
• What is a negative correlation


  relationship between variables where as one variable increases the other decreases e.g as temp increases, the number of hot water bottles bought decreases
• What is no correlation


  when two variables are said to be uncorrelated and have no relationship
• How are correlations displayed


  on scatter graphs

  the axis should be fully operationalised and labelled to indicate what co-variable they represent and how it was measured

  
• What can cause the relationship between 2 co-variables


  a third variable can affect the relationship between the co-variables e.g as the number of ice creams bought increases, the number of drownings increases -> the other variable that causes this relationship is hot weather
• What is a correlation co-efficient 


  tell us about the strength + direction of the relationship between 2 variables, refers to a scale between -1 and +1. +1 = perfect positive correlation and -1 = perfect negative correlation. 0 = no correlation
• Operationalise the variables: the older I get, the worse my memory gets


  V1 = age in years

  V2 = score on a word recall test out of 20
• Example of a one tailed correlational hypothesis

  There will be a negative correlation between the number of hours on average students spend on social networking sites per day and their GCSE English grade from 1-9, as a the number of hours spent on social networking sites increases the GCSE English grade decreases. (must operationalise)
• Example of a two tailed hypothesis


  There will be a significant relationship between the number of hours spent on social networking sites per day and GCSE English grades from 1-9.
• Example of a null hypothesis


  there will be no significant relationship between the number of hours on average students spend on social networking sites per day and their English GCSE grade from 1-9. Any relationship will be due to chance.
• strengths of conducting correlations


  +allows you to study the relationship between behaviours that would be unethical to manipulate = therefore correlations can be used in situations where an experiment would be unethical/impractical + upholds the rep of psychology

  +starting point of research to suggest/identify ideas from correlations = can create hypotheses for future experiments
• Weaknesses of conducting correlations 


  -no manipulation means you can't establish cause and effect = therefore future research is needed to establish cause and effect OR low IV as there could be a third variable responsible for the relationship which limits ability to use the research

  -other unknown variables may create the relationship between the co-variables = lowers IV as we aren't truly measuring what may have led to the correlation