cleaning, storing and summarising data

Question 1

what 3 things would you do to determine whether data is parametric or non-parametric?

Answer 1

1. plot a histogram
2. plot a QQ graph
3. carry out a Shapiro-wilk test

Question 2

how does does the Shapiro-wilk test test for parametric/non-parametric data?

Answer 2

accept or rejects normality in data and either accepts or rejects null hypothesis

Question 3

how do histograms help determine normality of data and what will more data achieve

Answer 3

the distribution of data can be observed- normal bell shape or other?
larger data sets ted to have a smoother curve

Question 4

should outliers be removed?

Answer 4

only if there is a definite reason for doing so- method was overtly wrong or a freak confounding variable skewed results

Question 5

how do QQ plots determine normality of data and what would a strong positive correlation suggest

Answer 5

data is plotted against theoretical values. a strong positive correlation would suggest normal data.