Search found 341 matches

by reason180
Wed Jul 02, 2025 2:38 pm
Forum: Module development
Topic: Incorrect effect-size value in paired t-test
Replies: 8
Views: 40018

Re: Incorrect effect-size value in paired t-test

@Ravi The esci module appears to be calculating an effect size (and CI) for the difference between two means computed from paired samples, somehow taking the pairing into account, but NOT simply calculating the effect size (and CI) for difference scores.
by reason180
Wed Jul 02, 2025 1:55 am
Forum: Statistics
Topic: Chi square post hoc tests and correction for multiple testing
Replies: 7
Views: 6372

Re: Chi square post hoc tests and correction for multiple testing

@Andrzej_Andrew It is also common, after a chi square analysis, to want to know about proportions or ratios pertaining to subsets of the data. For example, you might want to know, is A/(A+B) significantly different from 0.5: (i) for Malay, (ii) for Indian, (iii) for Chinese? The overall chi square a...
by reason180
Thu Jun 26, 2025 4:14 pm
Forum: jamovi development
Topic: Adjusted p-values for multiple comparisons
Replies: 5
Views: 13472

Re: Adjusted p-values for multiple comparisons

I believe p.adjust is already used for post-hoc tests *within* particular jamovi analyses such as ANOVA. The difficulty is, how to take pieces of the output (i.e., individual p values) from various separate analyses (a t test here, a chi square there, and correlation from somewhere else) and make th...
by reason180
Fri Jun 20, 2025 11:00 pm
Forum: Module development
Topic: Incorrect effect-size value in paired t-test
Replies: 8
Views: 40018

Re: Incorrect effect-size value in paired t-test

In checking some examples in jamovi, it appears that the effect size for the paired samples t test is being computed correctly based on the standard deviation of the difference scores (and nothing to do with pooling). The esci module appears to be doing something else--not calculating the effect siz...
by reason180
Fri Jun 20, 2025 2:36 pm
Forum: Module development
Topic: Incorrect effect-size value in paired t-test
Replies: 8
Views: 40018

Re: Incorrect effect-size value in paired t-test

Hi. I think something may be wrong there. A paired t test is equivalent to a one-sample t test on difference scores. Therefore there is only one SD describing the sample of difference scores: There aren't multiple sample-SDs that would need to be pooled. So the concept of pooling shouldn't be applic...
by reason180
Sat Jun 14, 2025 1:19 am
Forum: Help
Topic: Change Decimal separator
Replies: 6
Views: 4507

Re: Change Decimal separator

Using jamovi's Rj module you can simply write some R code like: setwd("c:/Temp/") write.csv2(data, "ToothGrowth.csv") Note that write.csv2 writes semicolon-separated values and uses the comma as the decimal character. The resulting file opens properly in Excel when Excel has been...
by reason180
Fri Jun 13, 2025 3:33 am
Forum: Help
Topic: Change Decimal separator
Replies: 6
Views: 4507

Re: Change Decimal separator

Just an FYI. You can change Excel's settings so that is uses the dot as the decimal separator:

https://support.microsoft.com/en-us/off ... bb9837bd1e
by reason180
Wed Mar 26, 2025 11:16 am
Forum: Help
Topic: Inconsistency in scale calculations
Replies: 11
Views: 116491

Re: Inconsistency in scale calculations

Hi. Thanks. To fix my example, there is only one item that is to be reverse-scored, and should be represented in my example as a column among several columns: 3243Untitled.png Yes, it ends up not mattering for correlation (reliability) computations because each column is ultimately converted to stan...
by reason180
Mon Mar 24, 2025 6:10 pm
Forum: Help
Topic: Inconsistency in scale calculations
Replies: 11
Views: 116491

Re: Inconsistency in scale calculations

Well, my suggestion was just the opposite: Always do the reverse scoring based on the theoretical not the actual range.
by reason180
Sun Mar 23, 2025 7:14 pm
Forum: Help
Topic: Inconsistency in scale calculations
Replies: 11
Views: 116491

Re: Inconsistency in scale calculations

RE "The choice of this adaptive method makes sense because the module cannot know the intended scale in advance." That's one way to look at it. But the way I see it, the only correct way to reverse-code is to base it on the theoretical, not the actual range of the data. For example, for -2...