And, by the way, you might find it useful to think of chance as being somewhat equivalent to the idea of error. When we can control sources of error, the likelihood that we can offer a meaningful explanation for some outcome increases. The second purpose of the null hypothesis is to provide a benchmark against which observed outcomes can be compared to see if these differences are due to some other factor. The null hypothesis helps to define a range within which any observed differences between groups can be attributed to chance (which is the null hypothesis’s contention) or are due to
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