Maths Skills

• What type of data is required for using the correlation coefficient?

  Continuous data
• When would you use the correlation coefficient?

  When looking for an association between two measurements
• What must you write for an investigation involving correlation coefficient?

  A null hypothesis
• What does a positive correlation indicate?

  Both variables increase together
• What does a negative correlation indicate?

  One variable increases while the other decreases
• What does an RS value of 0 indicate?

  No correlation at all
• What does an RS value of +1 indicate?

  Perfect positive correlation
• What does an RS value of -1 indicate?

  Perfect negative correlation
• What is the purpose of the critical value table?

  To determine if a correlation is significant
• What does a p-value of $0.05$ indicate?


  Less than 5% probability due to chance
• What does it mean if the calculated RS value is lower than the critical value?

  Accept the null hypothesis
• What conclusion can be drawn if the p-value is greater than $0.05$?


  Correlation is not significant
• How would you conclude if the RS value is $0.616$ and the critical value is $0.678$?


  Accept the null hypothesis
• What does overlapping data points in a scatter graph indicate?

  Range of results for the same variable
• How do you evaluate a conclusion based on statistical evidence?

  Use graph and statistic evidence
• What does a p-value of $0.01$ indicate?


  Less than 1% probability due to chance
• What are the steps to write a null hypothesis for correlation coefficient?

  1. State there is no significant correlation
  2. Specify the two variables involved
• What are the key components of evaluating a conclusion in statistics?

  • Identify supporting evidence from the graph
  • Identify evidence that contradicts the conclusion
  • Assess the significance of the correlation
• What is the significance of the correlation coefficient in biology?

  • Measures the strength and direction of association
  • Helps determine if a relationship is significant
• What is the process for calculating the Spearman's rank correlation coefficient?

  1. Rank the two sets of data
  2. Calculate the difference in ranks
  3. Square the differences and sum them
  4. Apply the formula to find RS value
• What is the relationship between RS value and critical value?

  • RS value must equal or exceed critical value for significance
  • Critical value is determined by p-value threshold
• What are the three statistics mentioned for A Level Biology?

  Correlation coefficient, student t-test, chi squared
• When would you use the student t-test?

  To investigate the difference between two means
• What type of data is required for the student t-test?

  Continuous data
• What does the null hypothesis state in a t-test?

  There is no difference between the two means
• What is the formula for calculating the student t-test?

  Not provided in the video
• What is the difference between a paired and unpaired student t-test?

  Paired uses data from the same individual
• How do you calculate degrees of freedom for an unpaired t-test?

  Sample one + sample two - 2
• What does a p-value indicate in a t-test?

  Probability that results are due to chance
• What is the critical p-value threshold for significance?

  0.05
• What does it mean if the calculated t-test value exceeds the critical value?

  Reject the null hypothesis
• What does a p-value greater than 0.05 indicate?

  Not a significant difference
• If a student calculated a t-test value of 4.82 with 2 degrees of freedom, what can they conclude?

  Reject the null hypothesis
• What does a p-value of less than 0.01 indicate?

  Less than 1% probability due to chance
• How do you evaluate the conclusion of a study based on p-values?

  Compare p-values to the significance threshold
• What does a significant increase in mean species richness indicate?

  Change in community structure
• What is the significance of a p-value less than 0.05?

  Indicates a significant result
• What are the steps to conclude a t-test analysis?

  • Calculate t-test value
  • Determine degrees of freedom
  • Compare t-test value to critical value
  • Assess p-value against 0.05 threshold
  • Accept or reject null hypothesis
• What are the implications of different p-values in habitat studies?

  • p-value < 0.05: significant change
  • p-value > 0.05: no significant change
  • p-value < 0.01: very significant change
• What is the role of the critical value in a t-test?

  • Determines significance of results
  • Threshold for rejecting null hypothesis
  • Based on degrees of freedom