how to conclude anova

Question

Hi Friends, I am looking for help as to how to interprete the data for one way anova for the following case senario...

I have 3 years batch data to be compared.. the batch data for 1st year was 30 batches, while for 2nd and 3rd year was 20 and 10 batches respectively... the P value is coming less than 0.05. Can someone suggest how should I interprete this result?

Mark_Bailey · Answer

Adding to Jim's reply, I assume that you are interested in the difference between years because you mention the number of batches per year (sample size). There are many things that you can do to understand, interpret, and decide about this data IN ADDITION TO THE ANOVA.

* Plot the data with Graph > Graph Builder. Plot Y versus Year. Use box plots and bar charts for individual or summary result.
* Plot and analyze your data with Analyze > Quality > Variability Chart for another nested view of Y versus Batch and Year. Many options in this platform.
* Plot your data with Analyze > Quality > Control Chart Builder for additional reference lines (natural control limits). Be sure to sort the data in time order or include a variable (time and date stamp) for each Batch in the X role.

txnelson · Answer

All that can be said is that you have a significant p-value.  More details need to be provided.  Are the data normally distributed? Are the variances equal.  What are the means of the different groups.  What were the results of the comparison between means.

A very good start in learning how to do all of these things, is to read the chapter on "Oneway Analysis" in the JMP Documentation

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