What is the difference between parametric and non-parametric stats tests?


What is the difference between parametric and non-parametric stats tests?
Different kinds or levels of data need to be analysed using different kinds of stats tests. The basic distinction between using a parametric or non-parametric test is between simple data:
Nominal – this means “named” data such as male/female, adult/juvenile, or tallies/counts of data such as the number of students taking maths at a college.
Ordinal – this means that your data is ordered in some simple way such as sea lions being classified as small, medium and large;
and complex data:
Interval – this is the same as ordinal data except that we know, for example, the actual length of small, medium and large sea-lions.
Ratio – this is the same as interval data except that it must make sense to have zero of the variable being measured. For example it is quite possible to get zero out of 20 in a math test but you cannot have zero personality, or zero height.

You also need to consider the distribution of your data before deciding upon a stats test. To use a parametric test data need to be normally distributed (form a bell shaped curve when plotted) – you can get your stats software programme to plot data for you, and check that the “skew” and “kurtosis” equal 1. If the data are not normally distributed and the skew and kurtosis do not equal 1 then you need to use a non-parametric test.

Posted Date: 2/20/2012 12:38:56 PM | Location : United States

Ask an Expert

Related Discussions:- Parametric and non-parametric stats tests, statistics, Assignment Help, Ask Question on Parametric and non-parametric stats tests, statistics, Get Answer, Expert's Help, Parametric and non-parametric stats tests, statistics Discussions

Write discussion on Parametric and non-parametric stats tests, statistics
Your posts are moderated

Write your message here..

Related Questions

..#title, formula for z test. formula for z test.

Quadratic frctions, y=4x-x^2 y=4x-x^2

Managing Ashland, calculate the probabilities correct to 6 decimal places. ... calculate the probabilities correct to 6 decimal places. Let pie = 0.02. a. P(X less than 3,

Accounting is an art of recording, Accounting is an art of recording Yes... Accounting is an art of recording Yes, we recognize upon that declaration because if we evaluate the primary features of the accounting program we will find that primary three p

Vital statistics, what are the methods of measuring mortality and fertility... what are the methods of measuring mortality and fertility rates?

Statistic, difference between histogram and historigram difference between histogram and historigram

Historigram, what is historigram. what is historigram.

Define block grant, Define block grant A federal grant that consolidates, ... Define block grant A federal grant that consolidates, for a wide reason or any type of purpose, funds previously awarded for a wide variety of activities.

Compute the z scores, 1. Compute the z scores for the following raw scores ... 1. Compute the z scores for the following raw scores where   = 78 and the standard deviation = 4. a. 72 b. 82 c. 78 d. 87 e. 71

What is owner’s equity, What is owner’s equity? Owner’s value is on... What is owner’s equity? Owner’s value is one of the three primary elements of a single proprietorship’s stability piece and bookkeeping situation. Owner’s value symbolizes