Does your doctor know? The table in given Exercise shows whether NEJM medical articles during various time periods included statistics or not. We're planning to do a chi-square test.
a) How many degrees of freedom are there?
b) The smallest expected count will be in the 1989/No cell. What is it?
c) Check the assumptions and conditions for inference.
Exercise :
Does your doctor know? A survey7 of articles from the New England Journal of Medicine (NEJM) classified them according to the principal statistics methods used. The articles recorded were all non-editorial articles appearing during the indicated years. Let's just look at whether these articles used statistics at all.
|
|
Publication Year
|
|
|
1978-79
|
1989
|
2004-05
|
Total
|
|
No stats
|
90
|
14
|
40
|
144
|
|
Stats
|
242
|
101
|
271
|
614
|
|
Total
|
332
|
115
|
311
|
758
|
Has there been a change in the use of Statistics over the decades?
a) What kind of test would be appropriate?
b) State the null and alternative hypotheses.