Multiple Select questions are a great way to get feedback in situations where either one or more than one response from a pre-determined set of selections is desired.

Demographics (ethnicity, origin, household composition, etc.)
Attribute questions
Store, Brand, and Product lists

Two Types of Multiple Select Questions

Multiple Select: This question type allows you to create an infinite number of answer choices to a specific question, with respondents choosing one or more responses.
Multiple Select Matrix: This question type is similar to the Multiple Select in that respondents may select one or more answer choices. However, Multiple Select Matrix allows set-up for a single scale used for multiple attributes in a table.

Programming Steps

From the New Question dropdown menu, select Multiple Select.

Next, enter and update the following:

Question text and a label, if desired (labels are not shown to respondents but can be used for back-end reporting).
Select clip icon to attach an image or video, if desired.
Select checkbox if you want to make the question required (all have to answer it to go to the next survey screen).

Other options include:

Select checkbox if you want to make it a Matrix question (used for multiple attributes that have the same answer option categories)
Max Choices allows to you to specify the maximum number of selection a respondent can make. For example, you may use a question: "Select the top 3 soap brands in the market." Setting Max Choices to "3" would prevent respondents from selecting more than 3 brands.
Switch type allows you to switch the question type from Multiple Select to Single Select.

Under "Choice," add the answer options. You may do this by typing in one at a time and choosing the + sign in the blue box to add others or simply press ENTER when done typing each choice. You may also choose BULK ADD to paste in a list of choices from another source. Again, labels can be added, if desired (labels are not shown to respondents but can be used for back-end reporting).
Select clip icon to attach an image or video, if desired.
Create Based-On Rule is a great advanced programming feature that allows you to show answer choices based on past member responses within this activity. For more details, read here.
A "none" option, a "don’t know" option and/or an "other" option can be added. These options will automatically be shown at the end of the list – even when the list is randomized.
Adding "why" field will add an open-end text box underneath the options. Note, the "why" field is not required even if the overall question is set as a required question.
Choices can be randomized, if applicable to research needs.
Click FINISHED to save the question.

Example Set-Up: Multiple Select

Set-up for a required, randomized Multiple Select with answer options, including “none,” “don’t know” and “other” listed in random order is shown below:

Once set-up is complete, the Preview below will show how the question will appear on the survey platform:

Example Set-Up: Multiple Select Max Choices

Set-up for a required, randomized Multiple Select question with Max Choices set at 3. There are also "none," "don't know" and "other" options:

When a respondent tries to select more than 3 answer options an error message will appear as shown below. You can check on this using the testing functionality for surveys.

Example Set-Up: Multiple Select Matrix

Set-up for a required, randomized Multiple Select Matrix with a table is shown. Note that Max Choices is set at 2, so respondents can select up to 2 months for any brand (Max Choices is enforced for each row separately, not for the entire table). Adjust number of Max Choices as desired. There is also a “none” option: