Research methods 7: Use of inferential statistics Flashcards
What does statistical analysis produce?
An observed value
What must you compare the observed value with?
The critical value
In a sign test, Mann Whitney and Wilcoxon the observed value needs to be…
equal or less than the critical value to be significant
In a chi-squared, Pearson’s r, both T tests and spearman’s Rho the observed value needs to be…
equal or greater than the critical value to be significant
What is the standard answer format?
As the observed value of ……………… is greater/less/equal to the critical value for a one/ two tailed test for N= (how many participants there are). The results are therefore significant/not significant at p<0.05/p<0.01. So…
What are degrees of freedom?
The number of independent values or quantities which can be assigned to a statistical distribution that are free to vary
What do you do if a stats table has no N column but instead a df column?
You must calculate the degrees of freedom and use that figure to read across your critical value table
When do you need to work out the df?
Only when using a Chi-square or either of the T-tests
What is the formula to calculate DF for a chi-square?
df = (r-1) x (c-1)
in df = (r-1) x (c-1), what does R and C represent?
Rows and Columns
What is the DF formula for a related T test?
df = N -1
What is the DF formula for a unrelated T test?
df = N1 +N2 - 2
What are the three DF formulas for…
-Chi-square
-Related T test
-Unrelated T test
-df = (r-1) x (c-1)
-df = N-1
-df = N1 + N2 – 2
Which test is an observed Rs value?
Spearman’s Rho
Which test is an observed S value?
Sign Test
