Statistics Notes: Quartiles, quintiles, centiles, and other quantiles

Quartiles, quintiles, centiles, and other quantiles.

Statistics notes: blinding in clinical trials and other studies.

Human behaviour is influenced by what we know or believe. In research there is a particular risk of expectation influencing findings, most obviously when there is some subjectivity in assessment, leading to biased results. Blinding (sometimes called masking) is used to try to eliminate such bias. It is a tenet of randomised controlled trials that the treatment allocation for each patient is not...

Statistics notes: variables and parameters.

the course of low back pain in general practice: a one year follow up study. Ann Rheum Dis 1998;57:13-9. 16 Croft PR, Papageorgiou AC, Ferry S, Thomas E, Jayson MIV, Silman AJ. Psychological distress and low back pain: Evidence from a prospective study in the general population. Spine 1996;20:2731-7. 17 Papageorgiou AC, Macfarlane GJ, Thomas E, Croft PR, Jayson MIV, Silman AJ. Psychosocial fact...

Statistics 240 Lecture Notes

So far, we have been concerned with nonparametric tests and procedures: tests and procedures with minimal assumptions about the probability distribution that gives rise to the data. Examples of the kinds of assumptions we have made in various places are that the distribution is continuous, that the observations are iid, that subjects are randomized into treatment and control, etc. We now consid...

Course Notes - Statistics