[BlindRUG] Interpreting QQ Plot nonvisually or alternative approaches

[misokwak12 at gmail.com]

Thank you for the response and tip on UniDesc() function, Jonathan.

My instructor and I are discussing other ways to do this particular part of
the assignment.

Both my instructor and I tried the UniDesc function after loading BrailleR
package, and couldn't seem to make it work.

I don't know what my instructor tried, but what I tried was 

`UniDesc(out.lm)` 

Where `out.lm` was my linear model .

Is there a different way I should use the `UniDesc()` function or any other
things I should be aware of?

 

Miso

 

From: BlindRUG <blindrug-bounces at nfbnet.org> On Behalf Of Jonathan Godfrey
via BlindRUG
Sent: Sunday, November 26, 2023 4:56 PM
To: Blind R Users Group <blindrug at nfbnet.org>
Cc: Jonathan Godfrey <A.J.Godfrey at massey.ac.nz>
Subject: Re: [BlindRUG] Interpreting QQ Plot nonvisually or alternative
approaches

 

Hello Miso,

 

I get asked this question a lot; far too often to be honest.

 

You mentioned residuals, so I am assuming your question relates to fitting
linear models (of any kind) using the `lm()` function.

 

There are four assumptions for the linear model, least important of which is
the normality of residuals. It is however the easiest one for sighted people
to assess courtesy of the normal quantile plot.

 

A lack of normality is often a symptom that another assumption is also
questionable.

 

Not having the correct model, constant variance, and independence of
residuals all have greater impact than the lack of normality. 

 

You can investigate most assumptions by way of fitting alternative models or
making use of various hypothesis tests (variance and independence), not to
forget the tests for normality. Many of these are used in the `UniDesc()`
function in the BrailleR package.

 

Jonathan

 

 

 

 

 

 

From: BlindRUG <blindrug-bounces at nfbnet.org
<mailto:blindrug-bounces at nfbnet.org> > On Behalf Of Miso Kwak via BlindRUG
Sent: Monday, November 27, 2023 10:58 AM
To: 'Blind R Users Group' <blindrug at nfbnet.org <mailto:blindrug at nfbnet.org>
>
Cc: misokwak12 at gmail.com <mailto:misokwak12 at gmail.com> 
Subject: [BlindRUG] Interpreting QQ Plot nonvisually or alternative
approaches

 

Hello,

Is there any way to understand a QQ Plot I produce in R nonvisually?

Or is there any comparable alternative that would allow me to make
interpretation on the distribution of residuals?

 

Thank you in advance.

Miso

 

 

 

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