Re: Fisher-Freeman-Halton Exact Test or Jonckheere–Terpstra test - which is the most appropriate?

Posted by Maguin, Eugene on Feb 16, 2016; 4:33pm
URL: http://spssx-discussion.165.s1.nabble.com/Fisher-Freeman-Halton-Exact-Test-or-Jonckheere-Terpstra-test-which-is-the-most-appropriate-tp5731524p5731534.html

Might this dataset be a candidate for a permutation or randomization approach? If used, it would not address ordinality issue. The only thing it would do is to say that the observed test value is at the 'x' percentile of the distribution of test values resulting from all permutations of the dataset. Gene Maguin

-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of DP_Sydney
Sent: Monday, February 15, 2016 8:57 PM
To: [hidden email]
Subject: Re: Fisher-Freeman-Halton Exact Test or Jonckheere–Terpstra test - which is the most appropriate?

Hi Rich and Raimundas,

Thanks for the comments.

The total sample size for the two tests is 40 (tail vs wing) and 80 (tail vs foreneck). The marginal distributions for each test are shown in the graphs below.
<http://spssx-discussion.1045642.n5.nabble.com/file/n5731529/SPSS_Discussion.png>
These distributions are bell-shaped for Test 1, and unimodal with a positive skew for Test 2. So you've convinced me that it is more appropriate to run a rank correlation on the data, which is also more intuitive (i.e. a correlation).

WRT to the Jonckheeere-Terpstra test, Rich you wrote "The JT test does not handle ties well ... I have not used it, but quick reading suggests that having a continuous outcome (and small N) are two of the expectations." I would like to read the text you refer to (this test may come in useful in the future, so I'm keen to learn more). I have not read anything about continuous outcomes, indeed the first reading I did about the JT test refers to its use in doubly-ordered contingency tables - i.e. ordinal dependent & ordinal independent (http://www.sussex.ac.uk/its/pdfs/SPSS_Exact_Tests_21.pdf). I'm also unsure what you mean by "ties".

Thanks also for the advice regarding the lack of power of the FFH Exact Test through it ignoring the ordinal nature of the variables, something I didn't
appreciate.  

Cheers,
Dean



--
View this message in context: http://spssx-discussion.1045642.n5.nabble.com/Fisher-Freeman-Halton-Exact-Test-or-Jonckheere-Terpstra-test-which-is-the-most-appropriate-tp5731524p5731529.html
Sent from the SPSSX Discussion mailing list archive at Nabble.com.

=====================
To manage your subscription to SPSSX-L, send a message to [hidden email] (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD

=====================
To manage your subscription to SPSSX-L, send a message to
[hidden email] (not to SPSSX-L), with no body text except the
command. To leave the list, send the command
SIGNOFF SPSSX-L
For a list of commands to manage subscriptions, send the command
INFO REFCARD