Thursday, August 5, 2010

Nonparametric Tests - When Should The Marketer Use Them

Nonparametric Tests

When To Use Them

in Marketing

Statistical procedures are either parametric or nonparametric. Parametric statistical tests require assumptions about the population from which the samples are drawn. For example, many tests such as the t Test, Chi-Square tests, z Tests, and F tests, and many types of hypothesis tests require the underlying population to be normally distributed. Some tests require equal variances of both populations.

Sometimes these assumptions cannot be always be assumed. Examples of this would be if the population is highly skewed or if the underlying distribution or variances were entirely unknown.

Nonparametric tests have no assumptions regarding distribution of underlying populations or variance. Most of this are very easy to perform but they are not usually as precise as parametric tests and the Null Hypothesis usually requires more evidence to be rejected in a nonparametric test.

When To Use Nonparametric Tests

Nonparametric tests are often used as shortcut replacements for more complicated parametric tests. You can quite often get a quick answer that requires little calculation by running a nonparametric test.

Nonparametric tests are often used when the data is ranked but cannot be quantified. For example, how would you quantify consumer rankings such as very satisfied, moderately satisfied, just satisfied, less than satisfied, dissatisfied?

Nonparametric tests can be applied when there are a lot of outliers that might skew the results. Nonparametric tests often evaluate medians rather than means and therefore if the data have one or two outliers, the outcome of the analysis is not affected.

They come in especially handy when dealing with non-numeric data, such as having customers rank products or attributes according to preference.

If you would like to create a link to this blog article, here is the link to copy for your convenience:

Nonparametric Tests - When Should the Marketer Use Them?

nonparametric tests in excel, non parametric tests in excel, normal distribution, normality tests, normally distributed, statistical tests in excel
Please post any comments you have on this article. Your opinion is highly valued!

If You Like This, Then Share It...
Dig this Stumble upon Delicious Technorati Reddit Buzz it Twitthis

Excel Master Series Blog Directory

Statistical Topics and Articles In Each Topic


  1. Well Said, you have furnished the right information that will be useful to anyone at all time. Thanks for sharing your Ideas.

    software testing course in chennai

  2. Great info. I love all the posts, I really enjoyed,
    nice post and site, good work!
    I would like more information about this, because it is very nice.
    java training in hyderabad

  3. I’m excited to uncover this page. I need to to thank you for ones time for this particularly fantastic read !! I definitely really liked every part of it and i also have you saved to fav to look at new information in your site.
    vé máy bay đi hồ nam trung quốc

    giá vé máy bay hà nội đi quảng châu

    vé máy bay tphcm đi thượng hải \vé máy bay hà nội đi thượng hải

    giá vé máy bay đi anh quốc

    đặt vé máy bay đi mỹ ở đâu

    vé máy bay từ mỹ về việt nam 2020