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

\( \bar {y} \)

\(\bar {y}=\frac {1}{T} \sum _{t=1}^{T} (y_{t}) \) : the mean for y values over T weeks

σ
^{2}

\( \sigma ^{2}=\frac {1}{T1} \sum _{t=1}^{T} (y_{t}\bar {y})^{2} \) : 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
_{
s
e
c
o
n
d−g
e
n
e
r
a
t
i
o
n
} 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}

\( GM(e)= \left (\prod _{i=1}^{n}(e_{i})\right)^{(1/n)} \) : 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
