Unit 8 – using statistics in science
D2 – Evaluate the validity of the interpretation of the results of the chi-squared test
“The chi squared test is a test is used to determine whether there is a statistically significant
difference between the expected frequencies and the observed frequencies in one or more
categories of a so-called contingency table” [Unknown. Chi-squared test]. Within the chi-squared
test there are aspects that cause limitations within the test and aspects that reduce reliability.
One of these aspects are the use of secondary the data. The data set was not collected
primarily and was taken from someone else’s findings. These findings that were collected have been
used for this experiment and it is unknown if the secondary data is 100% correct and accurate. This
will never be known as it is not possible to cross check the secondary data’s accuracy. This therefore
reduces the reliability as the chi-squared test could have incorrect answers due to incorrect data
given.
A limitation is the fact the chi-squared test is a non-parametric test which means the data does not
follow a distribution and no assumptions are made. It’s based entirely on the calculations and the
critical value. Competing 4 different calculations was tedious, and if a larger number of calculations
was needed, then chi-squared does limit this via strain of thought.
One other limitation that reduces reliability is the need for accuracy. Because it is calculation based,
it is best to input all the decimal places in order to achieve the correct answer for chi squared. With
inputting all these number for 4 different calculations, mistakes can be made, and they might not be
known. So, the answer for chi squared could actually be incorrect without realising and the reliability
decreases.
…………………………………………………………………………………………………………………………………………………….
Thank you for previewing the example, feel free to buy the singular task, or the Unit 8 bundle xxx
D2 – Evaluate the validity of the interpretation of the results of the chi-squared test
“The chi squared test is a test is used to determine whether there is a statistically significant
difference between the expected frequencies and the observed frequencies in one or more
categories of a so-called contingency table” [Unknown. Chi-squared test]. Within the chi-squared
test there are aspects that cause limitations within the test and aspects that reduce reliability.
One of these aspects are the use of secondary the data. The data set was not collected
primarily and was taken from someone else’s findings. These findings that were collected have been
used for this experiment and it is unknown if the secondary data is 100% correct and accurate. This
will never be known as it is not possible to cross check the secondary data’s accuracy. This therefore
reduces the reliability as the chi-squared test could have incorrect answers due to incorrect data
given.
A limitation is the fact the chi-squared test is a non-parametric test which means the data does not
follow a distribution and no assumptions are made. It’s based entirely on the calculations and the
critical value. Competing 4 different calculations was tedious, and if a larger number of calculations
was needed, then chi-squared does limit this via strain of thought.
One other limitation that reduces reliability is the need for accuracy. Because it is calculation based,
it is best to input all the decimal places in order to achieve the correct answer for chi squared. With
inputting all these number for 4 different calculations, mistakes can be made, and they might not be
known. So, the answer for chi squared could actually be incorrect without realising and the reliability
decreases.
…………………………………………………………………………………………………………………………………………………….
Thank you for previewing the example, feel free to buy the singular task, or the Unit 8 bundle xxx
