correlations

• What is a correlation?

  A mathematical technique investigating two variables
• What are co-variables in a correlation?

  Variables investigated within a correlation
• Why are co-variables not called independent and dependent variables?

  Because correlations do not show cause and effect
• What are the two general approaches used by Zheng and Cohn in their experiments?

  1. Deactivating cell receptors for hormones
  2. Boosting hormone levels in pregnant mice
• What was the outcome for male mice lacking testosterone receptors?

  They had shorter, feminine digit proportions
• How does testosterone affect cell division in the ring digit?

  It stimulates cell division to lengthen the digit
• What surprising factor influenced digit length according to the researchers?

  The balance of hormonal activity, not total levels

  
• What is the positive correlation between friends and happiness?

  More friends lead to increased happiness
• What is a negative correlation?

  Variables change in opposite directions
• What does a positive correlation indicate about two variables?

  They change in the same direction
• How can you determine if a correlation is positive or negative?

  By plotting a scattergraph of the data

  
• What does a correlation coefficient of 0 indicate?

  No relationship between the variables

  
• What does a correlation coefficient of +1 signify?

  A perfect positive correlation exists

  
• What does a correlation coefficient of -1 indicate?

  A perfect negative correlation exists

  
• Why are perfect correlations rare in the real world?

  Correlations are usually weaker in practice
• What are the advantages of using correlations in research?

  • No manipulation of variables needed
  • Safer and more ethical than experiments
  • High ecological validity from real-life data
• What are the problems associated with correlations?

  • Show only linear relationships
  • Do not indicate causation
  • Risk of misinterpreting relationships
• What is the "third variable" problem in correlations?

  Another variable may influence both variables
• How can one variable cause confusion in correlation analysis?

  It may influence both variables involved
• What is the challenge question regarding age and attitude to social care?

  • Create a scatter graph of age vs. attitude
  • Analyze the relationship for positive correlation

  
• What is required for a scatter graph to be marked accurately?

  Plots must be marked accurately
• What does a positive relationship between age and interest in social care suggest?

  Interest increases as people get older

  
• How do values of one co-variable relate to another in a positive correlation?

  As one increases, so does the other