TYPES OF LOGIC
There are 3 different types of logic in Magpi
1. Skip Logic
2. Message Logic
3. Calculation Logic
1 - Skip Logic
Skip logic routes respondents forward through the survey by skipping over sections of questions that are not relevant to a particular response. Magpi has two types of Skip Logic:
A. Jump To logic (very simple to create)
B. Advanced Skip Logic (a bit harder)
A - Jump To logic
Jump To logic is created by using the Jump To menus in the Response Options table of any multiple choice question. You simple pull down the menu and indicate where you'd like the user to jump to if the option in that row is chosen. In the example below, the designer has indicated that if Male is selected, the user will jump to question 23 (the end of the survey), but if Female is chosen, the user will jump to the next question (this is the default action).
B - Advanced Skip Logic
Advanced skip logic allows you to program much more complex logical skip patterns than just by using the Jump To menus. Advanced skip logic is accessed by clicking the Logic button on any question.
If-Then Skip Logic
The example above is of complex skip logic based on the value “Gender”. If the response is “Male” it will skip all non-relevant fields and jump to the end of the survey. The construction of the If Logic statement would be as follows:
If [Gender] has option selected ‘Male’ jump to [23)End of Survey]
This particular skip could be much more easily be created using the Jump To logic option detailed above.
If-Else Skip Logic
Advanced Skip Logic allows for more than one branch of Logic. The example below shows that a question about pregnancy can be designated to be displayed only if the response to the Gender selection is Female – and otherwise the user will jump to another question.
After the Logic statement has been created, click on “Save Logic” and then save the form.
2 - Message Logic
Message Logic is used to limit entries to a specific range or set of responses. If anything else is entered, a message pops-up on the screen, warning the user, and the user cannot proceed until the error is corrected.
3 - Calculation Logic
Calculation logic allows the designer to create complex calculations using mathematical operators: addition, subtraction, division, and multiplication. Parentheses are also available.
In the example below, the value of the current question is set to the combined value of two previous questions (current question = answer to Q12 + answer to Q14).
In the example below, a percentage is calculated by dividing two numbers, then multiplying by 100: