Hi Akila,

I use R to set letters or asterisks (or both) in my graphs. I use the HSD.test function + ggplot2 packaged and it works perfectly. This function performs all posible combinations automatically. Despite you have to know R language I totally recommend you to learn it. It's really useful and for a free-software enviroment.

Hope it helped.

Best wishes,

Victoria.

P.S.:here is an example of one of my plots.

P.S.: due to some people ask me about the R code I used, I leave here a link that could be useful. It's a function that I recently created which generates the tukey groups and asign them to the plot. 

https://github.com/vicruiser/tukey_test_plot

got one answer, In; Excel 2007, data labels are added through the "Data Labels" selection. As shown below, cells A2:A5 contain the data Items. Cells B2:B5 contain the data Values.

1) Select cells A2:B5

2) Select "Insert"

3) Select the desired "Column" type graph

4) Click on the graph to make sure it is selected, then select "Layout"

5) Select "Data Labels" ("Outside End" was selected below.)

If you don't want the Values as the Labels, you can click on the desired label, click twice so that it's the only thing selected, and then enter your new label information in the formula bar.

I recommend you to use some statistical software like SPSS or SAS rather using excel . And follow ANOVA or t-test for your data. then you'll get annotations for significant differences based on p value.

Akila, you write "I have several hundreds of statistical comparisons here". This sounds pretty much like a kind of a screening experiment (how would you otherwise formulate hundreds of well-thought hypotheses based on prior observations or models?). Hence, your scientific question is actually "WHICH of the following x-hundred comparison shows some difference?". Using null hypothesis tests straight away will give you a list of statistically significant differences, but MOST of them are likely to be false-positives (unless the majority of comparisons are anyway expected to show differences - but why do testing then?). In order to get an at least a little bit reliable result you must correct/adjust for multiple testing. Controlling the false discovery rate may be a good choice here.

Yoav Benjamini and Yosef Hochberg

Journal of the Royal Statistical Society. Series B (Methodological)

Vol. 57, No. 1 (1995), pp. 289-300

Further, the barplot is not well suited to show so many groups. Better use a dot chart instead. Another option is to show the DIFFERENCES along with their confidence intervals (CIs) directly, also as a dot chart. Then there is no "significance labelling" required: the CIs of significant differences do not include the zero. It is possible to adjust the CIs for multiple testing, too. However, I would not do this. Instead I would indicate which differences can be selected to keep the desired false-discovery rate (e.g. by filled vs. open markers, by color, by line width, or by a "star").

Dear Ajith & Jochen;

I just wanted to know after statistical analysis, how to show the significance differences (S.D) in bar plots? Because in SPSS 16 and Minitab 15 don't give this function ( to show any symbol above the bar). I've analysed the data (ANOVA), but the problem was when writing the paper to show the S.D. in chart? because I couldn't find any automated S/W to denote symbols above the bars?

The way I asked the question may wrong?

for a e.g. as shown in this image I wanted to show S.D. above the bars like A,B..., unfortunately I couldn't see any easy steps in SPSS / MINITAB?

I apologize that I did not answer your actual question. I don't use SPSS and I don't know the answer. But I hoped to give a useful comment on some other aspects related to barcharts, significance, and significance indicators. In case you won't be able to solve your original problem it might show you alternatives. Here is another one: If you have a lot of pairs (like those 3 pairs shown above) you might use a Bland-Altman plot to show the differences versus the averages.

GraphPad software is an alternative.

I haven't tried it. However, from the Prism guide of web pages, it can. All you need is to perform a statistic analysis and then copy and paste the asterisks shown in the result to your graph. In addition, you can draw a horizontal line cap. here are the links:

http://www.graphpad.com/guides/prism/5/user-guide/prism5help.html?stat_how_to_unpaired5_average.htm

http://www.graphpad.com/guides/prism/5/user-guide/prism5help.html?stat_how_to_unpaired5_average.htm

MOREOVER, it gives you a 30 day trial to see if it works or not.

http://www.graphpad.com/demos/

Hope it helps.

Hi Akila,

Would you please tell me how you got SD using SPSS? I really need help with this one. I used Tukey's method but my prof wants graph like you showed as your example. Would you please let me know? 

Thank you and Looking forward to hearing from you.

 Hi Tamalika,

Sorry to disappoint you. Still I don't have a answer for this :D 

What I do is using Excel Charts and labeling the selected bars and later rename the number according to letter I want ;)

if you found the method let me know

Hi Akila,

In Excel 2013 you create a separate column with your  labels.

Then go design/add chart element/data labels/more data label options.

Choose "value from cells" and select range from column with your labels, unheck "value". Your labels will appear above the graph bars.

I didn't find option to choose value from cells in Excel 2007.

Hi Akila,

I use R to set letters or asterisks (or both) in my graphs. I use the HSD.test function + ggplot2 packaged and it works perfectly. This function performs all posible combinations automatically. Despite you have to know R language I totally recommend you to learn it. It's really useful and for a free-software enviroment.

Hope it helped.

Best wishes,

Victoria.

P.S.:here is an example of one of my plots.

P.S.: due to some people ask me about the R code I used, I leave here a link that could be useful. It's a function that I recently created which generates the tukey groups and asign them to the plot. 

https://github.com/vicruiser/tukey_test_plot

What about STATA? Anyone knows if it will do it?

I found this interesting tool to extract data from Bar charts , thought maybe helpful :

http://pdfextractoronline.com/bar-charts-to-excel/#!

Hi Akila 

Im using grapher  8 from golden software, my version its pretty old but still suits perfectly. I have no problem todd the significant labels to my graph bars, and graph quality you get is for publication.

This is useful:

http://www.jerrydallal.com/lhsp/similar_prog.htm

Dear Akila Wijerathna Yapa,

      You can download Daniel's XL toolbox. Write down a b c d. then Select bar diagram. Go to "annotate". Then "Levels". Followed by  "These cells". "Annotate". Your work is done.

https://www.xltoolbox.net/

Thanks colleagues!

http://stackoverflow.com/questions/11889625/annotating-text-on-individual-facet-in-ggplot2

How to do in SPSS?

 http://www.r-graph-gallery.com/84-tukey-test/

This Rcode works for Simple ANOVA but I am not sure how to modify it to work for factorial design anova. Suggestions are welcome!!

Cheers,

Ayush

The statistical software Minitab provides the significance level with letters, you may put these letters(abc) on your graphs showing the level of significance.

 The R language shows the significance level with letters, but its command based and not so easy for new users. some other statical softwares shows the level of significance with abc.

Dear friend,

Here is a web application that resolve your problem easily,  BioVinci.

It could draw a high quality scientific figure in seconds and easy to add ANY symbols or text to the chart just by clicking on anywhere on the chart to open a text box.

You could try the two-way ANOVA example here: https://vinci.bioturing.com/panel/workset/build/Two-way-ANOVA

# 1 Run your model and get the summary

summary(MyModel

My favorite solution is using the asbio-package in R. The function pairw.anova or pairwise.kw allow to calculate posthoc-tests for ANOVA and Kruskall-Wallis tests. Then you can simply plot the results and it delivers the letters directly in the figure.

This can also be done manually in office word, insert picture- draw new canvas- copy and past your graph and using insert text you can write whatever you want to

You can use GraphPad Prism software in this context.

Akila Wijerathna Yapa Thanku your method of doing in excel was very helpful

https://my.originlab.com/forum/topic.asp?TOPIC_ID=10692

https://www.r-graph-gallery.com/84-tukey-test/

Add values on the bars, and then rename by selection of each individual value

Abolfazl Ghoodjani , Thank you very much, it worked out quite simple

In R, another way to get the letters on results is as follows:

summary(mymodel

Fakhria Wahid, what exactly is your question, can you be a little explicit with your question please? Are you using R or any other tool?

You can do that by using excel

Fakhria Wahid

Dear all, I have the same problem how to add letter of significance on bar graph drawn using sigma plot. Any one who can suggest how to do it please.

Thank you

i have same problem of adding aplhabtes and how it come in Grph pad prisam?

Hi all,

Does anyone know how to do it in SPSS please?

Thanks,