Suppose you want to do a chi-square test for independence in jamovi, but you only have summary data. Fortunately it is super easy to do that in jamovi. Here is how.
This example is based on a question from an assignment I use in my Applied Statistics course (the assignment itself is from the instructor resources of the book Introduction to the New Statistics (first edition)).
The introductory text to the question is as follows.
To what extent might feeling powerful make you less considerate of the perspective of others? In one study (Galinsky et al., 2006), participants were manipulated to feel either powerful (High Power) or powerless (Low Power). They were then asked to write an ‘E’ on their forehead with a washable marker. Those who wrote the ‘E’ to be correctly readable from their own perspective—looking from inside the head—were considered ego-centric (Ego); those who wrote it to be readable to others were considered to be non-ego-centric (Non-Ego).
Table 1 contains the data of the original study.
Table 1. Contingency table with the original data
Creating the dataset using summary data in jamovi
All you need to do is to a create a dataset with three variables. The first two variables are nominal variables. These variable define the rows and columns of your contingency table. Here, I opted for the variables Power, with levels 1 = High Power and 2 = Low Power and Perspective, with levels 1 = Ego and 2 = Non-Ego.
The third variable is the variable Counts (which can be nominal, ordinal and continuous, a far as I can tell). The count variable contains the number of observations for each combination of the two categorical variables.
This is what the dataset looks like:
Doing the chi-square test
If you have the dataset, the rest is super easy as well. Just choose Frequencies on the Analyses tab followed by Independent samples. Now place your row, columns and counts variables in the right spot, as in Figure 2. That’s all!
Last week, I taught a 5-day-course for the LOT (Landelijke Onderzoeksschool Taalwetenschap; Netherlands National Graduate School of Linguistics; www.lotschool.nl) introducing the new statistics to PhD-students working in linguistics and related fields of research. Links to the course materials can be found in this post (apologies for the many typos).
The day-to-day program was as follows.
Important concepts underlying statistics, like population paremeters, sampling, sanpling distribution, standard error and the margin of error. The primary means of developing these concepts was working with ESCI (www.tiny.cc/itns). The lab assignments are primarily based on Cumming and Calin-Jageman’s (2017) “Introduction to the new statistics”. The lab-assignments can be found here: www.tiny.cc/newstats. A pdf-version of the presentation can be found here: http://tiny.cc/newstats-presentation
Continuation of day 1. For students that finished the first assignment and to accommodate differences in backgrounds, new lab assignments focusing on statistical assumptions underlying the crucial concepts. Some of these assignments are based on Cumming and Calin-Jageman (2017) and ESCI, others work with R. The lab-assignments can be found here: www.tiny.cc/newstatsla2
Lecture only. In the lecture we reviewed the basic concepts discovered in the first two days. The concept of a confidence interval was introduced and the p-value. Furthermore, we discussed NHST by considering (at a procedural level and not so much on a statistical/philosophical level) how the procedure relates to its foundations: Fisher’s significance testing and Neyman and Pearson Hypothesis Testing. We basically saw that NHST is inconsistent with both of these foundations. We also discussed misinterpretations of p-values. The presentation can be found here: www.tiny.cc/newstatsday3. I also made available the lecture notes: www.tiny.cc/newstatsday3ln.
Lecture only. This day was about effect sizes. We considered the unstandardized difference between means, Cohen’s d, and the case level effect size measures Cohen’s U3 and the Common Language Effectsize. The powerpoint presentation is at www.tiny.cc/newstatsday4.
On the last day the students worked on new lab assignments focusing on interpretations of significance, the use of p-values and effect sizes in published work and working with effect size measures based on SPSS ANOVA output. These assignments can be found here: www.tiny.cc/newstatsday5.