Warning: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 726

Warning: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 729

Deprecated: Function get_magic_quotes_gpc() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 421

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/cookbook/recipecheck.php on line 80

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/cookbook/recipecheck.php on line 94

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Warning: Use of undefined constant MathJaxInlineCallback - assumed 'MathJaxInlineCallback' (this will throw an Error in a future version of PHP) in /cgihome/cis520/html/dynamic/2019/wiki/cookbook/MathJax.php on line 84

Warning: Use of undefined constant MathJaxEquationCallback - assumed 'MathJaxEquationCallback' (this will throw an Error in a future version of PHP) in /cgihome/cis520/html/dynamic/2019/wiki/cookbook/MathJax.php on line 88

Warning: Use of undefined constant MathJaxLatexeqrefCallback - assumed 'MathJaxLatexeqrefCallback' (this will throw an Error in a future version of PHP) in /cgihome/cis520/html/dynamic/2019/wiki/cookbook/MathJax.php on line 94

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/cookbook/wikipublisher/wikipublisher.php on line 1020

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/cookbook/wikipublisher/wikipublisher.php on line 1056

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/cookbook/wikipublisher/wikipublisher.php on line 1074

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/cookbook/analyze.php on line 89

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/scripts/skins.php on line 118

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Function create_function() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 484

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/scripts/pagelist.php on line 436

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/scripts/pagelist.php on line 486

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/scripts/pagelist.php on line 488

Deprecated: Function get_magic_quotes_gpc() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 421

Deprecated: Function get_magic_quotes_gpc() is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 421

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/scripts/upload.php on line 345

Deprecated: Array and string offset access syntax with curly braces is deprecated in /cgihome/cis520/html/dynamic/2019/wiki/scripts/upload.php on line 384

Warning: Cannot modify header information - headers already sent by (output started at /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php:484) in /cgihome/cis520/html/dynamic/2019/wiki/pmwiki.php on line 1304
CIS520 Machine Learning | Lectures / Glossary

Glossary

On this page… (hide)

B

↑ Contents

Bayes risk
Optimal (smallest) risk achievable by any predictor on a problem.

C

↑ Contents

Classification error or loss (aka 0/1 error or loss)
Used in classification to measure quality of predictor h(x): $\ell_{0/1}(h,y) = \textbf{1}(h(x) \ne y)$. We are often interested in 0–1 risk: $L_{0/1}(h) = \textbfĒ_(x,y)[\textbf{1}(h(x) \ne y)]$.
Conditional Independence
X is conditionally independent of Y given Z if $P(X=x \mid Y=y, Z=z)= P(X=x \mid Z=z), \; \forall x,y,z$ or equivalently, $P(X=x,Y=y\mid Z=z) = P(X=x\mid Z=z)P(Y=y\mid Z=z), \; \forall x,y,z$.

D

Decision stump
A decision tree with one internal node.

↑ Contents

I

↑ Contents

Independence
X is independent of Y if $P(X=x \mid Y=y)= P(X=x), \; \forall x,y$ or equivalently, $P(X=x,Y=y) = P(X=x)P(Y=y), \; \forall x,y$.

L

↑ Contents

Linear separability

A dataset $\{\textbf{x}_i,y_i\}_{i=1}^{n}$ is linearly separable if $$\exists w_0, \textbf{w}, {\rm such} \; {\rm that}: \left\{ \begin{align} w_0 + \textbf{w}^\top \textbf{x}_i > 0 &\; {\rm if}\; y_i=1
w_0 + \textbf{w}^\top \textbf{x}_i < 0 &\; {\rm if}\; y_i=0 \end{align} \right. $$

Loss
A function used to measure error of a predictor h(x), $\ell(h,y)$, for example, squared error or 0–1 error.

R

↑ Contents

Risk
Expected loss of a predictor h(x): $L(h) = \textbfĒ_(x,y)[\ell(h(x),y)]$.

S

↑ Contents

Squared error or loss
Often used in regression to measure quality of predictor h(x): $\ell_{2}(h,y) = (h(x) - y)^2$. We are usually interested in expected squared error, or risk: $L_2(h) = \textbfĒ_(x,y)[(h(x) - y)^2]$.

Back to Lectures