Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    18
    ReputationRep:
    I am so confused by the Chi-Squared Test!! How likely is it to come up in the exam tomo?
    Offline

    1
    ReputationRep:
    (Original post by Philip-flop)
    I am so confused by the Chi-Squared Test!! How likely is it to come up in the exam tomo?
    Do we even need to know that? I was told by my teachers that you did not need to know that for the AS exam.
    • Thread Starter
    Offline

    18
    ReputationRep:
    (Original post by aj122)
    Do we even need to know that? I was told by my teachers that you did not need to know that for the AS exam.
    Are you for definite? I just want to make sure. I'm so worried I don't know what to expect
    Offline

    2
    ReputationRep:
    The Chi-squared test is used when data is categoric and it is used to calculate the difference between the OBSERVED and EXPECTED details. It relates the number of individuals in particular categories and the calculation creates something called a "chi squared" value. The HIGHER the "chi squared" value calculated, the GREATER the difference between the observed and the expected results. Again, degrees of freedom can be calculated here (n-1) with n being the number of categories. Again, there will be a reference table and IF THE CHI SQUARED VALUE IS GREATER THAN THE CRITICAL VALUE then you REJECT the null hypothesis which shows that the probability that the results are due to chance is 5% or less AND THEREFORE this means THERE IS A CORRELATION BETWEEN THE DATA.
    • Thread Starter
    Offline

    18
    ReputationRep:
    (Original post by CrazyFool229)
    The Chi-squared test is used when data is categoric and it is used to calculate the difference between the OBSERVED and EXPECTED details. It relates the number of individuals in particular categories and the calculation creates something called a "chi squared" value. The HIGHER the "chi squared" value calculated, the GREATER the difference between the observed and the expected results. Again, degrees of freedom can be calculated here (n-1) with n being the number of categories. Again, there will be a reference table and IF THE CHI SQUARED VALUE IS GREATER THAN THE CRITICAL VALUE then you REJECT the null hypothesis which shows that the probability that the results are due to chance is 5% or less AND THEREFORE this means THERE IS A CORRELATION BETWEEN THE DATA.
    Thank you for the great explanation!!
    Do we need to know how to use the formula for the exam tomo?
    Offline

    2
    ReputationRep:
    (Original post by Philip-flop)
    Thank you for the great explanation!!
    Do we need to know how to use the formula for the exam tomo?
    I do the AQA Specification for AS Biology so I'm not sure about Edexcel.

    For AQA we don't need to know the calculations.
    Offline

    1
    ReputationRep:
    (Original post by Philip-flop)
    Thank you for the great explanation!!
    Do we need to know how to use the formula for the exam tomo?
    No, we shouldn't. It's not in the specification. However, Edexcel would be allowed to put it in the paper, they'd just get a load of angry teachers phoning them up to complain. But it's not that difficult to familiarise yourself, and if they do put it in the exams they won't expect you to know the equations and will provide it to you.
    Offline

    0
    ReputationRep:
    It is in the spec actually right at the bottom under Maths Skills, not that hard though.
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Would you like to hibernate through the winter months?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.