Testing Parametric Assumptions Flashcards
what do parametric tests assume?
- data is normally distributed
- groups have equal variance
- interval/ratio data
homogeneity of variance
equal variance
when can parametric tests be abused?
when data does not meet the underlying assumptions of tests
difference between non-parametric tests
- they do not make assumptions about population distributions
- less powerful and flexible than parametric tests
when is the kolmogrov-smirnov test used?
to determine the likelihood of data belonging to a normal distribution
k-s test: if the observed value is less than 0.05…
- this is significant
- not normally distributed
- parametric test cannot be used
k-s test: if the observed value is above 0.05…
- this is not significant
- data is normally distributed
- parametric test may be used
when is the levenes test used?
to test for homogeneity of variance, and determine data sets are from the same population
levenes test: if the probability is below 0.05…
- this is significant
- accept experimental hypothesis
- conclude there is not equal variance
levenes test: if the probability is above 0.05…
- not significant
- can assume there is equal variance
what is needed to perform a parametric test?
- normally distributed data
- equal variance between samples
report writing
- title
- abstract
- introduction
- method
- results
- discussion
- references
- appendices
title
provides a succinct statement of the core purpose of the research
abstract
short overview of the research (150-250 words) which states key variables, participants, and results
introduction
must introduce the general topic, theories relating to the topic, relevant research, and the specific hypothesis
