In this step, you define the formula parameters for the input values of calculated characteristics.

You can do this in two ways:

- the formula parameters directly reference the fields in the input characteristics

- the formula parameters reference function modules, which calculate the values in the fields of the input characteristics

**Example**

To determine the difference between the mean values of two characteristics or samples, you need the mean values of both characteristics or samples as input values. Since these mean values are available in the characteristic record, you can reference the corresponding fields in the input characteristics directly.

To determine how many values for a quantitative characteristic are above a target value, you need a special function module that calculates this using a counting function.

**Standard settings**

The system contains several predefined formula parameters that are often required. The table of field names has the delivery class E. The following name range is reserved for the user:

- Field names Q*, ..., Z*

**Recommendation**

Do not attempt to complete this table in advance. Do this only as the need arises.

**Activities**

1. If necessary, determine which
formula parameters are needed for a calculated characteristic and
check whether these parameters have already been preset in the
table.

2. If a formula parameter does not
yet exist, you must first define it and then decide:

a) whether you can reference a field
in the characteristics records, or

b) whether the value of an input
characteristic must be calculated with the help of a function
module

3. The characteristic fields you can
reference to calculate the values have been predefined
comprehensively in the system. Only in certain exceptions will you
need to expand this selection of fields.

**Further notes**

You can reference any desired fields in the tables of characteristic results in order to calculate the values:

- QAMR Summarized results for a characteristic

- QASR Summarized results for a sample

- QASE Single values for a characteristic or sample