Table 1.

Notation and Symbols

Symbol	Definition
y(t)	number of new cases of disease in the t th week observed in surveillance data
x(t)	number of new cases of disease in the t th week predicted by forecasting methods
x start	number of new cases of disease predicted at the start of epidemic season
x peak	predicted value of the maximum number of new cases of the disease
e t	e t=y t−x t : the prediction error
T	duration of the epidemic season
$\overline{y}$	$\overline{y}=\frac{1}{T}\sum _{t=1}^T\left(y_t\right)$ : the mean for y values over T weeks
σ 2	${\sigma }^2=\frac{1}{T-1}\sum _{t=1}^T{(y_t-\overline{y})}^2$ : The variance of y values over T weeks
n tot	Total number of infected persons during specified period
n ps	The population size at the start of specified period
n tot(a g e)	Total number of infected persons with specific age during the specified period
n ps(a g e)	The population size with specific age at the start of specified period
n c	or n contacts is the number of contacts of primary infected persons
n sg	or n second−generation is the new number of infected persons among the contacts of primary infected individuals during a specified period
G M{E r r o r}	$\mathit{\text{GM}}\left(e\right)={\left(\prod _{i=1}^n\left(e_i\right)\right)}^{(1/n)}$ : Geometric Mean of a set of Errors
M{E r r o r}	Arithmetic Mean of a set of Errors
M d{E r r o r}	Median value of a set of Errors
R M S{E r r o r}	Root Mean Square of a set of Errors