turn on suggestions

Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

Showing results for

- JMP User Community
- :
- Discussions
- :
- Discriminant analysis in JMP: meaning of misclassi...

Topic Options

- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Get Direct Link
- Email to a Friend
- Report Inappropriate Content

A week ago
(63 views)

*Context:*

When performing the multivariates analysis called discriminant analysis in JMP, the score Summaries give a number of "Misclassified observations". The user manual pdf "multivariate methods" define the following:

**Number Misclassified**: Provides the number of observations in the specified set that are incorrectly classified.**Percent Misclassified**: Provides the percent of observations in the specified set that are incorrectly classified.

**Prob(Pred)**: Estimated probability of the observation’s predicted classification.

*Question*

It is unclear to me** on what basis an observation is well classified or not**. In other words, which this the true criteria behind the "misclassified"?

*Possible answers?*

1) Maybe it is Prob(Pred), but again, how is it calculated?

For instance, is it calculated from the following definitions (given in the "saved formula" section)

1) qt prior probability of membership for group t

2) the p(t|y) posterior probability that y belongs to group t is defined.

Thanks for your answers

1 REPLY

- Mark as New
- Bookmark
- Subscribe
- Subscribe to RSS Feed
- Get Direct Link
- Email to a Friend
- Report Inappropriate Content

A week ago
(38 views)

Discriminant analysis is a form of *supervised learning*. You provide a *known response* with the training data set. The discriminant analysis results in a *predictive model*. The *predicted response* is compared to the given response. If they don't match, then that observation is considered misclassified.

Learn it once, use it forever!