|
<< Click to Display Table of Contents >> Navigation: User Guide > Project definition > Filters > Applying a filter |
Often a question is not asked for everyone in a survey. Some questions will only be asked if certain answers were given to earlier questions. This is often called "routing" or "filtering".
This a two stage process:
•Create a filter entry with a definition of those who should see the question
•Apply the filter entry to the question
IMPORTANT: this is the only way to implement routing. You can apply routing to responses, see Entry details window, "Responses" tab but this is only used for printing questionnaires; it is not used in data input or analysis.
Up to 10 filter entries can be applied to a question and the definition must be true for all of them if the question is to be asked. Put another way, there is an implied AND combining applied filters.
If more than one filter is applied to a question, then you can also specify a base text in the Entry details window to be used to describe those passing all the applied filters.
It is possible to negatively apply a filter. This means that the definition must NOT be true, if the question is to be asked.
TIP: it is possible to add positive filters by dragging them from the main window list and dropping them in the appropriate place.
Filter entries can also be applied to variables.
When filters are applied to variables, the variable will be empty unless all the filters are passed. Only if all the applied filter definitions are true will any responses or value be set in the variable.
It is possible to negatively apply a filter. This means that if the variable is to be evaluated the definition must NOT be true.
You can apply a filter entry to individual question responses. The response will only be accepted if the response filter is true.
Only one filter entry can be applied to a response.
TIP: it is possible to add filters by dragging them from the main window list and dropping them onto the responses in the responses tab.
Response restrictors do not use filter entries. They control which responses are available to be selected based on answers to earlier questions.
An applied response restrictor can be a question or variable with responses (single-coded or multi-coded). Each response in the question being asked is only allowed if the response is selected (or the definition is true) in all the applied response restrictor entries.
It is possible to negatively apply a response restrictor. This means that the response is available if the response is NOT selected in the restrictor.
It is usual for some responses (for example "None" or "Don't know") to be set to ignore any response restrictors because these should always be available for selection.
Applying a response restrictor does not alter who gets asked the question (routing).
TIP: it is possible to add restrictors by dragging them from the main window list and dropping them in the appropriate place.
Filters and new filter definitions can be applied to individual tables and globally in Tables setup.
If entries that have filters applied to them are used in analysis these will normally also be applied to tables using the entry as the rows, and optionally as the columns.
In Data drill down filters are applied to tables and used in Distinction analysis.